Does anyone know if the trans in a 56 olds will work behind a 1963 394? Thank you

 

As I understand it or remember you will need to open up the pilot bearing for the jetaway to seat it all the way in. I helped a friend do this about 45 years ago and there was much more than just opening up the bearring though but the options were not available back then. Somewhere on the net is a detailed description of what is needed , maybe on the H.A.M.B. forum. You might do a search if no one speaks up. I think the flex plate is different tooth and the starter must match it. One is a external balanced engine (324) and the other is a internal balanced (394) so there are issues there. Seems there were clearance issues with the manifold and steering box because of the higher deck height There are other problems but It's been to long ago to remember.... Tedd

 

Thank you for the reply. Through my research I believe the trans from the 56 is stronger than the 63. I’m just looking at options trying to figure out the best way to go. If its too costly or difficult i will just buy the adapter to put a Muncie 4 speed in it. Next question is i have found a few duel quad intakes for reasonable. If i use 2 500cfm edelbrocks is that too much for a stock 394?

 

Yes the slim jim usually sucks and depending if you have a slant pan or a jet a way (both could be had in 56) if given the choice I prefer the slant pan for durability and the Jet a way for smoothness of shifting both are better than a slim jim..... Tedd

 

A lot depends on the type of trans in your '56 .
The "dual coupling " AKA "Jetaway" has a "park" position .
The "dual range" AKA "slant pan" does not have " park ".
Is there a "Park" position on the quadrant ?

 

I don’t have the car yet. I am going over the holiday weekend to look at it. I’m trying to get information so i know if i need a car with a drivetrain or if i can buy a roller. I do have the engine, i drove 3 hours to get a car with a usable 394. I’m hoping to have something together for the hot rod power tour next year.

 

For a stock 394 yes , for a 394 with a high lift , longer duration camshaft no.
I would recommend about .500 lift and 230 degrees at .050 lift .

Talk to Tony at Ross Racing Engines ;
http://rossracingengines.com/
He is the "guru" of 394's .

 

If you are going to build a Hot rod , You will need to start looking for a 57 thru 60 Olds or Pontiac rear end to put under it
The 57 - 60 rear had a 9.3 in ring gear and posi is available ; https://fabcraftmetalworks.com/produ...ot--Rear-Ends/

The stock '56 rear end is much smaller , and may not handle the torque . Besides which there is no posi available .

 

Thanks for the tip on the rear end. Who is a good supplier for suspension, brake parts?

 

I looked in my Hollander interchange manual and found this notation ;
" Auto wreckers say complete rear axle assembly 1955 thru 1957 Olds & Pontiac will interchange by using original rear u-joint yoke . "
It appears that a '57 Olds (or Pontiac ) rear axle assembly will bolt right up to the '56 stock springs with only the yoke change .
One could also have a custom driveshaft made , negating the need to change the yoke .

You will need custom 31 spline axles to use the aforementioned posi unit in a '57 axle assembly .
Dutchman has them ; http://www.dutchmanaxles.com/ebaysto...-gm-car/sr222/

 

The trans in the car i got does have the park position on the indicator. The car has 49,000 miles on it and i checked the fluid and it looks good, does not smell burnt. Will this be a usable trans behind a 350ish hp 394? Thank you

 

What you have is a "dual coupling " AKA " Jetaway" trans .
It is a good rugged trans that will handle 350 HP .
You will need to swap the flywheel (0.666) for a 57 thru 60 flywheel with an "offset balance " weight .
The 57 thru 64 371 & 394 engines were "externally balanced " with weights on the flywheel and crankshaft pulley .
You will need to use your '56 starter and starter housing , as well as grinding the block slightly to clear the larger flywheel on '61 thru 64 engines .



While the "Jetaway" was a good rugged trans it was never a favorite of the performance crowd .
It's slow and sometimes quirky shifting disqualified it .
A Turbo-Hydramatic 400 is a much better choice and Ross Racing Engines makes the best kit on the market to adapt a TH 400 to a 394 ;
http://rossracingengines.com/c/5/old...early-catalog/