[Stuart]

If the slim jim is properly rebuilt by someone who knows what they're doing, it should be good for 100,000 miles - however, they always did shift 'funny' (they kind of slide from one gear to the next, and the 1-2 shift is a weird big jump in ratios) so they just never had the performance of a TH400. I'd agree that except for maybe with a 100 point restoration, swapping to the TH400 makes more sense and will make the car a lot more enjoyable and reliable.

[Keith Seymore]

Originally Posted by Stuart

If the slim jim is properly rebuilt by someone who knows what they're doing, it should be good for 100,000 miles - however, they always did shift 'funny' (they kind of slide from one gear to the next, and the 1-2 shift is a weird big jump in ratios) so they just never had the performance of a TH400. I'd agree that except for maybe with a 100 point restoration, swapping to the TH400 makes more sense and will make the car a lot more enjoyable and reliable.

x 2.

My impression is that the Slim Jim is not a very enjoyable trans even when functioning to design intent (which mine didn't).

The TH400 swap was not bad. I got mine used out of a '76 Riv for $75. The only expense for me was a starter mounting plate (since the starter mounts on the trans bellhousing in '63) which if yours is a '64 you may not have to deal with.

K