Have hot rodders come up with a way to replace the old slim jim automatic with a more modern one with a torque converter. Bendsten's has an adaptor that will run 800 with shipping and it might be the only option but was wondering if there is an alternative. The slim jim is in a 62 Pontiac with a 389. Thanks; Evan
Did the conversion to a TH400 in my '63 Cat using the Bendtsen's adapter, never again. I would highly recommend using the Wilcap adapter instead. Another alternative is using a later model engine. The '64 389 should be drilled and tapped for a block mounted starter which would allow you to use the TH400 w\o an adapter. Or go with a '65 and newer. Considering the cost of the adapter the later model '65 to mid 70's Pontiac engine & trans may actually be cost effective if you can find a decent priced combo.
The name given to the Hydra-Matic As Tubby says, I second that http://www.wilcap.com/pontiac.html#389350
I replaced the one in my 63' Safari with a T-10. Used a borrowed pedal set and z-bar as a pattern and made new ones. I saw a 63' 421 GP with a TH400. The owner fabbed a bracket to hold the starter since neither the block, nor the bell housing had privisions for starter mounting. You could also find a superhydramatic, still not as friendly as a TH400, but much better than the slim jim.
Cast iron. 4 speed automatic. I had one in my 62' Bonneville. Soft, mushy shifting, but I understand they can be made to shift firmer. My 59' Catalina had one as well.
The bellhousing bolt pattern is the same 61 and up. Find a BOP bolt pattern 350/400 and Butler Performance sells a plate for 250 that the starter bolts to. Just like the blueprint below...
When my "slim jim" failed in my old '62 Safari wagon the Hollander manual recomended I use a trans from a Star Chief. There was one other model that worked also. Both from the factory and both Hydra-matics. Check an old Hollander book at the salvage yard.
The "slim jim" does have a torque converter, it just doesn't look like the "regular" kind. The slim jim(roto-hydro) is a lousy trans. Awkward ratio spacing and poor shift quality aside, the trans has a horrible durability record. The iron Hydra-Matics were tough by comparison, but expensive to make. If I remember correctly the slim jim cost 1/3 what it cost to make the earlier iron one. Unfortunately they went too far and ended up with a pos. Money spent repairing your slim jim would be more wisely spent on an upgrade/swap. For older stock cars with low power the lower first gear in the earlier iron Hydra-matic is a plus. Otherwise, I would go with a TH 400. The slim jim wasn't made very long and was replaced by the vastly superior TH 400. So, one point in your favor, pretty much any trans you are likely to consider putting in the car would be better than what you have now.
huh heard you could snap into one , didnt know you could replace em ? . with what beef jerky , ? oooooooh yaaah
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