Originally posted by raven61:
The 250 was originally a powerglide motor, but I wish to run my S-10 5 speed behind it.
I got an early V8 bellhousing that has the mounting tabs on the sides and the removed the lower part of the starter mounts in order for the bellhousing to bolt up to the 250 with the 250's original starter in place. Then I obtained a flywhell (of unknown origin, I think it's a SBC). the Flywhell measures approx. 14 1/4" in diameter but my 250 flex plate measures 12 7/8". So now the flywhell hits the starter on the 250. Also, the bellhousing is 1/2" shallower than the original 235's bellhousing and I'm thinking that this will be a problem for my already modified 5 speed.
On the flywheel/flexplate thing, there are 2 different sizes...you seem to have found that out. The smaller one is a 153 tooth, and the larger is a 168. It depends what you want keep as far as which flywheel you use. If you already have a 12" (I think) clutch, then you'll need to use the 168 tooth f/w and replace the starter. If you still need to get a clutch and want to go with the smaller f/w, you'll be able to use the old starter.
On the starters, they are distinguished by the pattern of the bolts that fasten to the block. I can never remember which is which, tho. Straight across for the 168 tooth and diagonal for the 153 or the other way around. In either case, if you're gonna swap starters, make sure your block is drilled for both types of bolt patterns. (3 holes) If not, that will probably decide which one you go with, unless you buy an expensive mini-starter.
I hope that made sense. I went thru the same thing when I put a 355 and Saginaw 4-speed into my 63 Nova. I had a 168 tooth f/w, a large clutch and had to search for a starter to fit. Then I had to change to a Chevy II bellhousing to get the clutch arm at the proper angle and ended up with a 153 tooth f/w and a smaller (10"?) clutch. Ohh..and a different starter. Since I got all the parts to play nicely together, it's worked fine....exept for that broken Z-bar.