I just started down the restoration adventure of my 1950 1/2-Ton 3100 and am considering an engine swap. It currently has a 235 and according to the previous owner it ran a couple of years ago. Originally I was just thinking I would replace it with a V8 but have since come to like the straight six. So my current debate is whether to proceed putting money into the 235 or bite the bullet and put it into something a little larger. Unfortunately there are no 261s to be found but I have come across a couple 292s for sale. One of the 291s came out of a truck that the person bought to get the cab and other parts off of. The owner states there is a rebuilder tag and the head is off the engine and fresh bore new pistons can be seen. He did not however see the engine run . This person wants 800 for it. The engine casting number 93411147. I cant find much information on this number except the block does say "Hecho en Mexico". The second 292 is believed to be from a 1981 and based on the casting number 93406004 is possible. According to the individual he bought it without seeing it run and was intending on using it but went a different direction. He wants 600.
Obviously there significant risk here but is there some checks I could perform to better ensure the engines were probably ok?
292's have massive amounts of torque and they respond well to go fast modifications, but they do tend to be gas hogs. They share the same bellhousing bolt pattern with the V8's so you'll need to do some mount modifications- - - -a crossmember change and a 55-up V8 bellhousing is one approach to the swap. Of course, it's also going to require an open driveline, so the entire running gear will end up getting changed out. Have fun! 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!
I'm not too concerned about the fuel since it won't be a daily driver but all of the mods associated with it are a bit discouraging. Im trying to keep the truck mostly original (except engine of course) without cutting anything off such as the crossmember. The 261 would be so much easier but I guess that is the reason they are hard to come by.
In regards to the cost of the 291s are they to pricey? I have seems couple up north that are a lot cheaper but I think the market in the Dallas area drives prices up. Also, what could be done to check the engine since it isn't running? Compression?...
Unless I can hear an engine run, I'm reluctant to call it anything better than a "Rebuildable core" and pay an appropriate price. I also don't draw to an inside straight in a poker game. 292's aren't that scarce, compared to 261's so if you pass on one or both of these, another one at a better price is likely to come along. Do a little bargaining with a fistful of 20's- - - - -money talks! 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!
It is more work installing a 292 than it is to install a small block V8. You can buy a 350 crate motor tomorrow, or you can buy a 'pig in a poke' 292 or a 261 and end up spending more money to rebuild either of those engines than what a crate 350 costs. Here is a pic of my '49 3100 with a dressed up 1974 "Thrift Master" 350 in the engine bay.
Last edited by 52Carl; 09/04/201711:17 PM.
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
I put a 292 into a 68 gmc because I got a good deal on a recently overhauled engine and we had a 67 with a 292 when I was a kid and it seemed like a real hoss compared to the 230 in our other truck. It runs great and seems like it's going to be a good engine but I really wish it was a 250. The 292 is similar to the other 6's in that family but just enough different to be a pain in the rear. I was fortunate enough to come up with engine stands and a power steering set up but if you're just doing this in your free time like me it can be difficult to find some of these things. I plan to put AC on this truck and that's going to be another adventure. For a truck that's not going to be pulling a trailer or hauling a load I think a 250 is much easier to deal with and probably more economical.
'64 swb stepside (gone) '57 1 ton '53 phone truck '59 swb '46 1 1/2 ton '68 swb gmc
