The Stovebolt Site Forums The Parking Lot Big Bolts bolt up old tranny to new engine

i cannot for the life of me get any secondary motor to lift my dump bed. so, i really need to use the original transmission, but the engine is dead. i have an 85' 305 chevy that i want to bolt up to the old tranny for the power takeoff.
can anyone point me in the direction for adapter kits?

An SM465 will bolt right up to that motor, is cheap and plentiful, and has a PTO on each side. That could be an easier option than an adapter.

Also 420's, 540 series, etc.

Ed

Putting a SBC in your truck and saving the SM-420 transmission and it's PTO will require a new bellhousing (1958-up? truck) and new motor mounts/crossmembers (fabrication).

Why not find a 261 and replace the bad engine? It's a direct bolt in with no fabrication required!

Mike B

thanks for the excellent answers guys. I'm making this a daily-ish driver that i want to use for many years to come. so i kinda need something i can get parts for more readily, hence the engine swap, as opposed to just getting an original replacement. also, thank you for the tranny suggest, i love the idea of dual pto, i could really make use of that!

could you give me some more information? an initial search has only turned up one for sale on ebay, with local pickup only. so, i kinda need to know what trucks have these, so i can yard hunt for one. many thanx

SM420 was used in GM trucks till 67, then they went to the SM465. (40# heavier, about 1.6" longer, and not as low granny and PTO on both sides, plus a backup light switch!) You should be able to get the tranny and bellhousing etc from a newer truck and drop in there. Is this going in your 49? How about park brake? a tranny out of a 1/2 or 3/4 ton won't have the park brake on it as the park brake was on the rear wheels

305 V8 isn't a big truck motor, 1/2 pick up about as big a G.M. ever put them in.
I'd keep it inline, 235 or 261.

Things to think about:

PTO's are not all interchangable, the internal driven gear needs to match the host transmission. The PTO off of a Clark transmission will look the same (SAE 6 Bolt), but won't work on the GM transmissions.

Motor mounts...you existing setup has the transmission hanging off of the bellhousing with four motor mount points (2 up front and 2 at the bellhousing). The modern SBC will have 2 side mounts and one on the transmission tailshaft. Make sure you have a plan before you start buying stuff as it might not bolt right in.

If you rebuild a 235/361 and the existing SM420 you'll have years and years of dependable service. They are simple to work on when needed and parts can be mailordered overnight from lots of vendors.

Mike B

if im making more torque, and more horse than the original engine, what would be the problem?

50 2 ton. park brake cables still intact for the rear two speed axle. i need to keep it simple and cheap for now.

Depends how hard you work the load on the PTO. PTO's of sizes in question all have the same 6 bolt mount(there are larger ones) so that is why they all look the same from the mounting point of view, however, the meshing gears are all different, that is why they are trans. specific, not stamped anywhere. PTO shops have mount details based on casting numbers, tooth count, tooth angle, gear position.

Ed

Ed, when a guy's got his mind made up, don't try to confuse him with facts!
LOL!
Jerry

that's rude. i dont have my mind made up about anything. i'm trying to figure out what could work, and not. i'm asking questions for clarification.

I see you're asking questions about HP for the hydraulic pump...

Rather than spending lots of money making a work around, why not just spent that money on a running 235. You can buy a good running motor for less than $500...install it and be done with everything working as designed...just a thought!

Mike B

I am putting a 454 and turbo 400 in my 49 6400 I know that there will be fabrication involved but I'm not scared. I will start a new thread and post pictures as it goes

because i cant find one locally, after shipping etc, im outside of 2K$ and rebuild kits start at 1500$. i'm just kinda using parts i have on hand. i have a 3hp small motor, but it couldnt do the job, even though i can turn it by hand, apparently the speed adds load.

got any links for where to order parts from? my own research hasnt been promising.

What parts for what transmission/etc?

i hate to sound so vague, but anything for these 50's trucks. hard to find new parts at all, outside of new body panels.

Novak in SLC has 420 parts, good reputation. Search yards for other hard parts, or whole items, 'net for repair items.

Ed