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Discussion Starter · #1 ·
Another annoying question from a Newbie. I plan on bolting an old SM420 to the backside of my 4BT. It fits using the standard bellhousing that came with the tranny, however it appears that there may be some interference with the starter when it's engaged. This is one of the old GM cast iron bell housings that's open on the bottom as opposed to the full cast aluminium bellhousings that found on some of the SM-465 trannies.

Anyone have any experience with this problem? I'd like to stick with this bellhousing as it has a good place to attach the rear mounts for the transmission. There is no mount on the rear of the SM420.

Thanks, Dan
 

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Do you have the starter spacer between the starter and the adapter?
 

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Discussion Starter · #3 ·
Thanks for the suggestion, I'll have to check tonight when I get home. The motor/starter/flywheel/adapter is all intact just as it was when pulled from a running vehicle. It just seems that when I get this wired up and try to start it, that the starter gear may rub the bell housing. I'll take a pic tonight an post it.
 

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Discussion Starter · #4 ·
Yup, spacer is there. Looks to be about 5/8" thick. So here's the question. How far back does the starter pinion gear move when it engages the flywheel? If is doesn't go back any farther than the rear edge of the flywheel ring gear I'll be ok. If it goes back any farther than the mating surface of the GM adapter/bellhousing interface I may have interference problems with the SM420 bellhousing.
 
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