Swapping TH350 to m20, 153 flexplate to 168 tooth flywheel.

Do i need to change my starter? I went to autozone and they ask whether its a manual or auto but nothing about tooth count. I know there is a difference in material type between auto and manual however I just want to get htis thing back on the road (its my daily driver) while I wait for a new starter to show up from summit or jegs.

i think that your bell housing might be a factor, not positive. The 168 tooth #621 bell you will need the staggard bolt pattern starter...someone else might chime in

There are only two aluminum GM passenger car bells which are large enough for a 168 tooth flywheel. Both need the iron nosed, staggered bolt starter.

I have a truck bellhousing in there, when test fitting there was no clearance issue at all, fit perfect cleared the starter fine.

is bellhousing clearance the factor?

If you use a truck bell, do you have to make sure that M20 has the larger bearing retainer? Isn't the hole in the bell larger on truck bell housings?

I have an adapter to make the hole the correct size.

once again, is bellhousing clearance the factor when it comes to having to change starters? This bellhousing is probably as big as they come, it clears the starter with room to spare.