hammerit

Hi all. It has been awhile since I have been on this site but I am getting ready to tackle the big project. I have a bueatiful 1964 Jet Star one that is all done (body and interior). the engine is making noise and the slim-jim does not shift properly. I have read many posts on the conversion to a modern engine and th 400 combo but I need the difinitive answer as to the problems that may be encounted. Many of the posts say no problem and most of them are speaking about non- slimjim years of cars. Cars that have more trans tunnel clearence then cars built from 60-64. As I understand it Olds was very proud to be able to make the slimjim cars very low with out a tall trans hump because of the small compact design of the slimjim. This leaves very little room in the trans tunnel for anything else. My interior is all done and I hate to think about ripping the tunnel up. Please if there are any peole who have done this swap with a SLIM-JIM CAR I would love to get a step by step once and for all that the site could refer all further questions on this subject to. I know so many people hate the slim-jim and I am going to have both the engine and trany sitting on my floor in a few days I sure could use some help in making the discission. Thanks so much.

64Rocket

You might also consider a 350/403 small block & T-350 combo.
Also 394 & slim-jim does not mount the same as the late model OLDS & trans. You will need your mechanical ability, not a hard job to convert.
If it was me, I would give it a lot of thought, some planning, and then go for it.

Gene

rocketraider

You will have to fabricate mounts for the later engine and trans as 394 mount very differently. Find a 1964 Jetstar 88 and look at the engine mounting for its 330 and Jetaway to gain an idea of what you will have to do.

Most of the tunnel clearance problems I've read about involved putting a THM on a 394 with an adapter, which pushes the transmission farther back in the chassis. KQQLCAT has a thread on here showing his Ross adapter kit THM side by side with a Slim Jim and they look to be about the same length and even height at the tailshaft area. Even so he had to alter the crossmember some to fit.

Another thread showed how a guy had to cut up his Starfire's tunnel to make a T400 fit. Sounds like this isn't really an option for you.

I agree with Coldwar. For a J-I, rebuild what you have and you will have preserved the car's integrity. Part of what made a Jetstar I special was its Starfire drivetrain. Without it, it might as well be a Jetstar 88. The big issue with SJ is finding someone competent to rebuild them who is not afraid of them because of their reputation, and then getting the TV rod adjustments right.

hammerit

The car is very nice, a low mile desert car from down the road from me. I think that I will keep it stock. I have 2 other engines and one other Slim-jim so perhaps with those and a lot of money I can get it done. Are there any Slim-jim people in California who can do the rebuild? I will be pulling the pan to see if it is a bearing that can be replaced if so then that will be it. The engine runs sooo good and does not burn a bit of oil I am hoping that it is a simple fix. If not it will be taken out. It starts with 50-60 lbs oil presure and then when it is hot it goes down to 3 lbs. No engine noise until you are driving and give it the gas then a noise that I have never heard before. With out a load on it you can rev it all you want and no noise. Strange. Can't wait to find out what it is. The slim-jim just shifts from 1st to 3rd other then that it is fine. Thanks for the responses.

hammerit

I only have one (1) shift. It goes from a normal 1st gear to very tall gear when it does shift into drive. When it does shift into drive it is so tall (3d gear) that it accually lugs the engine. So it is shifting from 1st to mechanical 3d grear. No 2nd gear. Other then that thereis no noise in the tranny and it does every hting like it is supposed to. When you stop it goes back to 1st gear. Because of the great torque that the 394 has I could almost live with the 1st to 3d shift if I can perhaps only have to do a bearing or piston on the engine and leave well enough alone on the tranny. I will have it up on stands in the garage on Sat. and will start the detective work then. I'm sure I will be back on here on Monday with lots of questions. I wonder if a dirty filter in the tranny would make it skip 2nd gear? Nah, too easy. Thanks

hammerit

Thanks for the advice. With age I am getting some patience, I can follow directions, I have a nice place to work, and have most common tools. So with all that said, I will probably burn it in the front yard Sat night. LOL Can't wait to dig into it and I do have the manual that seems to be quite good compared to some of the other manufacturers. Although it is all hocus pocus to me now I hope to learn a lot more about the slim jim before I am done.