The Stovebolt Site Forums The Shop Area Engine Shop Engine swap! 235 to v8

I have a 1946 cehvy coe and I want to keep the stock trans and install the v8. Is it possible to keep the stock trans? Its equiped with the pto for the lift bed and I dont want to lose this. I also observed that late 80's GM used the HM-117 (MUNCIE) for bus and straight truck but I dont know if pto is possible for this trans.Trying not to use adapter plates for trans to bellhousing witch is what Im guessing will have to happen. Fabrication is not a problem but Im trying to keep the rest of the truck as OE as possible except for the enging for more power and work.

All you big truck masters please help me on this Im new to the big trucks but have a big passion for them.

You can use a 55-72 v-8 bell housing. You will have to modify the frame where the mounts on the bell housing goes or put a universal crossmember under the engine. There is some variations in the size of the collar on the trans. where it fits in the bell housing. Some of the other Stovebolters are familiar with this & will jump in & help out.

I think the bell housing you need is the 55-59 V8 truck. It has mounts built in. similar to the stock bell housing. It is a cast iron housing. You can also use a pass car from the same time, but the mounting configuration of the truck may be closer to what you need.

Wrenchbender Ret and Lonnie Gallaher Thanks for the inforamation. Thats a load off my back and lots of comfort to replace it. Glad to have this board available

Measure the bearing retainer on the trans you plan to use. The bellhousing center hole on the 55-67 is a little under 5" and the 68-72 is about 5 1/4". Fred

Wasn't there a transmission design change in '48? I don't know for sure, but I'm not sure your transmission will bolt to the later bellhousing.

The SM420 will bolt to that later bell, and if you get one from a big truck, or from a '55 to '67 it will be open drive and still have the PTO support.

rfs56trk, thanks for spec I will do just that. OldSub , change in design is what Im afraid of, something tells me that for the time in mind with the build of these trucks there is a great chance of what your saying.

Thanks for all your input guys and as I follow up on all the info I will return with pics and updates as to what I have found.

You guys are great , thanks alot.

I think the trans change from 47 1st series to the 47 2nd. The Art Deco trans had a trigger on the shifter for reverse. I don't know if it has the same mounting pattern as the "SM" series transmissions found in the Advanced Design trucks.

A sm465 will work too, it has PTO previsions on both sides of the trans. Only noticable difference would be reverse being to the right and down instead of the left,
Scott

The 465 has the larger bellhousing bore index, due to the larger bearing retainer.

I guess you would have to swap the bell out too. Forgot about that. That would take some mount fabricating since the bell's flange is bevelled up instead of horizontal to the crossmember. Not hard, I just made some for BradB's 47 panel.

48, do you have any pics of the mounts you fabed for using the angled bellhousing with the horizontal crossmember? Looking at doing this same swap in my 53 GMC 350 series and had thought about changing the crossmember to the later type but if mounts can be made easily might try that.thanks

They actually make side mounts that will go on a V8 ,I don't know who makes them tho, I made my own for my 53. For the front I used a tranny cross member from a 73-77 chevelle and front V8 mounts from a 57 Chevy car. The cross has the perfect dip and angle for the 57 mounting system.All you have to do is measure the width between the frame at the front and cut it to width and weld flanges to the ends and bolt it thru the side of the frame.Don't forget you'll have to move your steering box over 1 3/4 " .For exhaust I used 2 driverside exhaust manifolds from 77 Nova's.One dumps behind the box, and the other dumps in the front.

48bigtrucks and longbox55 Thanks for the welth of knowledge. Ill be posting in the wants for a sm465 of years 55-67. Also scrounging the salvage yards in my area. Thanks again


CAJUN CRAW FISH.

obsa,
Here is the only picture I have of them, hope you can see them.
Scott

Nice mounts, nothing wrong with saving a few bucks. I need to purchase a larger brake so I can bend some heavy gauge metal.

48bigtrucks and longbox55 I found my trans through a company in midwest for 750 completely rebuilt with upgrades to prevent gear jumping and 1 year warranty. Will see what happens in a weeks time. Thanks again for the info.

Scott , thanks for the pic solved a lot of questions nice work by the way.

Hi,
I am just getting into older trucks and find myself with information I know nothing about. I am in the process of buying a 6 cylinder for my 57 pickup. Someone put a 350 and changed the hubs to 5 lug so now I need to start collecting the parts to return it to its former glory. At any rate on the passenger side of the engine below the distributor and starting from the left there are many objects and numbers on the engine block. Can anyone decipher this “language”?


CON 2
Next there is a teardrop with 3 letters around it pointing at “N” at 0 degrees, “T” at 120 degrees and ”D” at 270 degrees.
Next there is a oblonged circle with E19 in the center.
Next there is another teardrop surrounded by 12 dots in a circle with one dot at the 12 o'clock position outside the circle.
Next the numbers 3921968 and below that GM and below that 57.
Can anyone tell me what all this means?
Thanks,
New to trucking,
humblejack