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| | | | Joined: Jul 2002 Posts: 385 'Bolter | | 'Bolter Joined: Jul 2002 Posts: 385 | After wasting nearly a year trying to find a shop near Seattle that will rebuild my 248, I've decided the best way to keep my truck on the road is to shove one of these 250 Chevy blocks into the truck. Who has done this swap, what resources do you recommend, what should I avoid, and how much blood loss can I expect? | | | | | Joined: Sep 2010 Posts: 1,705 back yard wrench turner | | back yard wrench turner Joined: Sep 2010 Posts: 1,705 | I did the opposite, put a GMC in my Chevy.
I had to move the radiator forward, drill a new hole for the front motor mount. Everything else fit. I imagine the exhaust will need attention.
Wayne1938 1-Ton Farm TruckStovebolt Gallery Forums1989 Silverado 1996 Mustang GT convertible When I die, I hope she doesn't sell everything for what I told her I paid for it! | | | | | Joined: Jun 2011 Posts: 5,096 Crusing in the Passing Lane | | Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | I have an extra 302 that would fit.
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
| | | | | Joined: Jul 2002 Posts: 385 'Bolter | | 'Bolter Joined: Jul 2002 Posts: 385 | I'm getting the feeling that all the 'bolters who have done this swap are out driving their trucks and not hanging around the forum. I've got a month or so to do research while I wait for delivery, so if anyone has documentation of a similar swap please drop a link. Like everything else on this truck, I'll make it fit. [img] https://i.imgflip.com/144h75.jpg[/img]
Last edited by Hedgehog; 02/28/2021 3:28 PM.
| | | | | Joined: Jan 2001 Posts: 5,337 'Bolter | | 'Bolter Joined: Jan 2001 Posts: 5,337 | It is not that bad of a job with the right parts.
Using a 1963-72(I believe) bellhousing, the mounts will fit your truck. The transmission will also bolt up.
It has been a good many years since I did this, and I seem to remember needing the correct combo for the front bearing retainer on the transmission, and hole size in the bellhousing.
You will need to adapt engine side mounts.
See the USA in your vintage Chevrolet! My Blog | | | | | Joined: Dec 2018 Posts: 2,450 'Bolter | | 'Bolter Joined: Dec 2018 Posts: 2,450 | Hedgehog Once got a lesson on those sixes,we had a head come in ,ground the valvesand used aircraft magnaflux on it which was far superior to "dust"magnaflux (had been hot) shortly they came back antifreeze in the oil ! It wasn't long till it took a shortblock (same head)fixed it. Not much later we smelled a rat from a report from someone else. Went and looked at that core, lifter bores cracked,so watch your heat !! | | | | | Joined: Jun 2011 Posts: 5,096 Crusing in the Passing Lane | | Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | If your trans has a 4.875” retainer diameter and your bell housing is 5.125”, Advance Adapters in Paso Robles has a sleeve to make up the difference.
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
| | | | | Joined: Jul 2002 Posts: 385 'Bolter | | 'Bolter Joined: Jul 2002 Posts: 385 | If your trans has a 4.875” retainer diameter and your bell housing is 5.125”, Advance Adapters in Paso Robles has a sleeve to make up the difference.
Ed Not gonna keep the SM420, the new motor will have a 4L60 auto behind it. That means none of the existing engine and trans mounts will work, and the front half of the driveshaft needs whittling.
Last edited by Hedgehog; 03/02/2021 2:29 PM.
| | | | | Joined: Jul 2002 Posts: 385 'Bolter | | 'Bolter Joined: Jul 2002 Posts: 385 | Well, that plan lasted until they checked the warehouse inventory at Summit. No more inlines are available, they no longer have a source for rebuildable blocks. Refund is pending. Back to square one. | | | | | Joined: Feb 2004 Posts: 29,778 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,778 | If you're planning to go to all the effort to do a complete drivetrain swap, why not use a 292 engine? Those are still available for various types of farm equipment applications, either brand new or factory remanufactured. I believe they're still being built new in Mexico or Brazil for either Massey-Ferguson or John Deere.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
| | | | | Joined: Jul 2002 Posts: 385 'Bolter | | 'Bolter Joined: Jul 2002 Posts: 385 | If you're planning to go to all the effort to do a complete drivetrain swap, why not use a 292 engine? Those are still available for various types of farm equipment applications, either brand new or factory remanufactured. I believe they're still being built new in Mexico or Brazil for either Massey-Ferguson or John Deere.
Jerry source? | | | | | Joined: Jun 2011 Posts: 5,096 Crusing in the Passing Lane | | Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | 292’s are easy to spot when searching, make sure one is looking at a ‘63 or later, check the tappet cover, 292’s are about 6” tall, 194, 230, 250 are all much shorter.
Right side engine mount off set from left side, does not matchup to left side.
Ed
Last edited by EdPruss; 03/21/2021 1:24 AM.
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
| | | | | Joined: May 2005 Posts: 8,983 Sir Searchalot | | Sir Searchalot Joined: May 2005 Posts: 8,983 | Buy any newer motor you want. There is no problem. Once you get a motor and a trans that fits the motor, the rest is easy. Mock it up in there, using a universal tubular cross member motor mount and trans mount. When all done, have the drive shaft lengthened or shortened with proper slip joint/yokes. Piece of cake. You will work out any interferences like steering box, firewall, radiator, linkages and you will notice any other issues at mock up stage. Many folks have swapped motors into AD and TF and 60-66 trucks but there is no recipe or detailed instruction. Just be confident that there is plenty of room and plenty of help with any issue that pops up. You will be happier and have more options and parts available with a SBC donor.
I do realize you are on a budget but you seem committed to a modern automatic and a new long block or donor motor factored into your budget.
You are committed to new motor mounts and trans mounts already. It's a good plan. The cost is all about wheeling and dealing and DIY.
Buy the stuff, take off front clip and mock up. Take your time and sit there with the mock up and make friends with it.
I put a 454/350TH in a 56 GMC...........and added 4x4 to stock frame and body. It's all just grunt work and some fab. Mock up is absolutely necessary. Everything hangs in there on cherry pickers, blocks and jacks until you see all is well, motor is level and pinion angle is good. (broom handle)
The tubular cross member motor mount and trans mount eliminate a whole lot of fabbing and screwing around.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
| | | | | Joined: Jul 2002 Posts: 385 'Bolter | | 'Bolter Joined: Jul 2002 Posts: 385 | I do realize you are on a budget but you seem committed to a modern automatic and a new long block or donor motor factored into your budget.
You are committed to new motor mounts and trans mounts already. It's a good plan. The cost is all about wheeling and dealing and DIY.
Buy the stuff, take off front clip and mock up. Take your time and sit there with the mock up and make friends with it. I'm needing the automatic because I'm going to hand controls only, my good leg ain't so good these days and the tonner clutch is a bit stiff. I love the smooth, quiet operation of the inline six, I can DIY a carb and points, and I don't want to re-engineer the fuel and cooling systems. A long block from a reputable builder would be preferred, because if I had the time or space to rebuild a GMC block I'd do the running 248 that's in the truck rather than buy a second set of problems. I may rebuild the 248 later if the head isn't wrecked, I'll figure that out once I determine if there's a running block w/auto trans available to fill the gap. There's a strong possibility this will be the last project I do at this address if I disassemble the truck in the parking lot. Eviction proceedings take around three months, I don't know if I can get the new driveline installed in time.  | | | | | Joined: May 2005 Posts: 8,983 Sir Searchalot | | Sir Searchalot Joined: May 2005 Posts: 8,983 | You are approaching a "Catch 22". Something has to give. What is actually wrong with your 248?
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
| | | | | Joined: Jul 2002 Posts: 385 'Bolter | | 'Bolter Joined: Jul 2002 Posts: 385 | You are approaching a "Catch 22". Something has to give. What is actually wrong with your 248? Spooky ectoplasm keeps appearing behind me and poltergeists come knocking in Winter.
Last edited by Hedgehog; 03/21/2021 5:01 AM. Reason: /url, dammit
| | | | | Joined: May 2005 Posts: 8,983 Sir Searchalot | | Sir Searchalot Joined: May 2005 Posts: 8,983 |
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
| | | | | Joined: Jul 2002 Posts: 385 'Bolter | | 'Bolter Joined: Jul 2002 Posts: 385 | Still looking for that link to a freshly rebuilt 292 for sale, which several of you believe exists. Your rhetorical belief in this fabled 292, without any hard evidence... may be signs of a religious cult. 
Last edited by Hedgehog; 03/21/2021 2:38 PM.
| | | | | Joined: Nov 1995 Posts: 5,716 62401 | | 62401 Joined: Nov 1995 Posts: 5,716 | Steve -- I think you should ask Ed some more questions about his 302 he's offering you ... Do you still have access to your friend's garage? And be advised that you seem to want to do to your truck is not a simple weekend project and will most likely put you in violation of your HOA/Lease *especially* if you pursue an unusual configuration (then Bart's suggestion of the mocking up process is the only way you will succeed).
Just sayin' ... 'cause there might be a slight disconnect between what you want to hear and what you need to hear. Take what these guys are trying to tell you to heart. They truly are trying to help.
We're here for you, regardless.
John
~ John A kid raised on Hotwheels, Matchbox and Tonka cannot be reasonably expected to own only one vehicle as an adult. 1949 Chevrolet 3804In the Legacy Gallery | In the Gallery Forum1973 IH 1310 Dump1963 Kaiser M38A12001 International/AmTran RE3000 "Skoolie"2014 Ford E-350 4x4 (Quigley) | | | | | Joined: Jul 2002 Posts: 385 'Bolter | | 'Bolter Joined: Jul 2002 Posts: 385 | The donor transmission has a working V6 already attached, and as a last resort I can transplant the cooling and fuel systems and computer box from the 96 chev. That's just gonna be a few extra weeks (months) of plumbing and wiring. Sourcing a rebuilt inline long-block would have made the engine and driveline an affordable job, and would minimize the time I'm without transportation. I was beyond disappointed when Summit cancelled my purchase, they can no longer find inline cores. That's why I am doggedly pursuing every rumour of inline long blocks for sale. I'm definitely going to be asking after Ed's 302 as soon as I get my dinero back from Summit. I saw no evidence of Hecho En Mexico inlines sold through tractor suppliers, and the marine vendors only do heads, pumps and covers for the 250. No cores available. The advantage to the 4.3L would be power everything and AC. If I can't source a "new" block, I will end up with a small budget to rent work space, bypassing the parking lot issue. The engine has around 130K on the odo and I'd be doubling the mass it's dragging, so it'll wear out pretty soon as well. Subsequent swaps would be easier, crate 4.3L V6 are still sold via mail-order. But then again, so were re-manufactured inlines just a year ago. | | | | | Joined: Jun 2011 Posts: 5,096 Crusing in the Passing Lane | | Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | Hedgehog,
If going automatic, you will need a torque converter, also.
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
| | | | | Joined: Jul 2002 Posts: 385 'Bolter | | 'Bolter Joined: Jul 2002 Posts: 385 | Hedgehog,
If going automatic, you will need a torque converter, also.
Ed Yep, nearly $300 for a RV/towing converter for the 4L60E. These nickels and dimes are the size of manhole covers. | | | | | Joined: Jun 2011 Posts: 5,096 Crusing in the Passing Lane | | Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | Does your 248 have a 4 bolt crank or a 6 bolt crank? That would be a place to start. If you are just going to drive around town, a 250 Chevy would do the job, slip-it in there and go. If you find a 292 someday, easy replace with new right front engine mount, 3 bolt exhaust flange.
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
| | | | | Joined: Mar 2004 Posts: 6,214 'Bolter | | 'Bolter Joined: Mar 2004 Posts: 6,214 | A quick web search shows Jeg's and the big auction site have 292's in stock if that's what you want. Mike B  | | | | | Joined: Jul 2002 Posts: 385 'Bolter | | 'Bolter Joined: Jul 2002 Posts: 385 | A quick web search shows Jeg's and the big auction site have 292's in stock if that's what you want. Mike B YES! Link me, please, I searched JEGS and the only inlines I saw listed were Toyota. edit: I told the webpage AI I drove a 1970 Checker and it spat out this page. Is this what you were talking about?
Last edited by Hedgehog; 03/22/2021 2:41 PM.
| | | | | Joined: Mar 2004 Posts: 6,214 'Bolter | | 'Bolter Joined: Mar 2004 Posts: 6,214 | | | | | | Joined: Jul 2002 Posts: 385 'Bolter | | 'Bolter Joined: Jul 2002 Posts: 385 | Thank you!  | | |
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