I have a 62 star fire and am looking to replace the transmission seeing as it just recently died on me. because it's a slim jim it has been a pain trying to find anyone who will even touch the damn thing so i'm looking to replace it with the th350 or 400. I am open to any suggestions because i'm still VERY new to this and would like some professional advice. I was looking to purchase the transmission through summit racing. So some questions i have would be, what other parts would need to be replaced when swapping a transmission? mind you, i want to COMPLETELY replace the transmission. also what modifications would i need to make to the vehicle itself. After doing some research i noticed most people said the cross members and driveshaft but they were for different model and year olds? and last, most of the th350's on summit specify a vehicle such as chevy or pontiac. does that mean something as far as having it mounted? like I said I'm really new to this and am pretty lost. any help would be greatly appreciated

 

Nothing else will bolt in easily except another SlimJim. Even a 4-speed Jetaway HydraMatic will probably require some transmission tunnel work. All other GM transmissions require modifying the case to attach it to the Rocket engine plus whatever mods have to be made to get the unit to fit in the car.

The Rocket engine/ SJ combo uses a three point mounting system- a front motor mount under the engine's timing cover, and two transmission mounts at the rear sides of it. You will have to figure a way to mount it stably in the car.

Search for KQQLCAT' s posts on here. He put a Turbo 400 in his 61 and had a great pic thread about it.

I don't understand a transmission guy who will rebuild an electronically controlled unit but is scared shitless of a Slim Jim. If he can repair a PowerGlide or a Chrysler Torqueflite, a Roto HydraMatic shouldn't be a big deal as they operate on much the same principles.

 

The early dual range (single coupling) hydramatic will also bolt to the 394. However it is just a big in diameter as the DC hydro is, so the tunnel thing is still affected.

 

It was a rare option but you could get a manual trans in this car from the dealership.

 

Worm, it is almost as easy to find someone to work on a Slim Jim as to find a 61-64 big Olds stick setup!

 

Wrong info here. You couldn't get a manual in a Starfire

 

It wasnt a Starfire option but it will still bolt up to a 394. I read that in 88 series cars the manual was column shift so you would have to get real lucky and find a column or do some custom work. And your right it would be alot easiser and cheaper to have the slimjim rebuilt. I found a place that will convert th350, th400, powerglide and a couple other trans cases to match a 394, it's about $1000 just for the case modification. They also sell a manual trans kit for about the same price(you provide the trans).

 

http://www.transmissionadapters.com/Pricing.htm

 

We know from the big car salesmen data books and chassis parts manuals that standard shift was available in Super 88, Dynamic 88, and Dynamic 88 Fiesta wagon, but only in the wagon with L-65 regular fuel engine, and those then having 3.23 axle ratio as ratio with SS. The Jetaway fits with no floor pan work to at least 1962, I know this only because I have been involved in this swap several times down through the years, and I highly recommend this as this is a huge step up in enjoyment and durability. In 1963-64 they lowered the tunnel further, moved the engine/trans assy forward in chassis to gain further clearance, with revised engine front end housing/water pump/fuel pump and drivers exh manifold for duals. I know cars were converted to factory SS even when nearly new, as one personal example I have pedals removed from a 1962 Starfire which was a one-owner part out. There are too many examples of 1961-64 SS big cars around to conclude most were cobbled together much later, so I'm pure guessing some accomodating dealers may have done this work on a special order basis augmenting those made and sold. It would be terrific if a order or invoice showing such work would turn up as reference.

If you must go to a T-400 I recommend the Ross Racing conversion. It is a much shorter assy overall saving some floor mods, and it is bolt in with no tramming or alignment needed. They modify the case for the install to save length, you can buy it from them empty, or rebuilt and ready to go. They have a reliable trans shop they work with for these jobs. I am told with using a long tailshaft trans a one-piece driveshaft is possible on nearly stock ride height 61-64 big cars, a very definate plus, but I haven't had the chance to examine one built that way.