My 70 ss396 will be getting a TKO 600 this spring. I dont know if it has a 153 or 168 tooth flywheel and I want to get correct parts on order. The drive train is a mixture of many different parts and years so I have to physically identify what I have in car. From the forum I see that 153 teeth flywheels have the starter with the straight across bolts and 168 teeth have staggered bolts. If the starter is a GM or some type of replacement starter is this always the case? If I take off the dust cover can I measure the flywheel? Is there any way to tell the flywheel size from the distance to the teeth on the flywheel to the bellhousing? Would it help to know the bellhousing part number, hopefully it is on the outside of the bellhousing. The problem is the car is in winter storage and I can get under it and look at the starter and bellhousing but I cant take anything apart. At worst case I could probably order both Pressure plates and disk sets and return one set.

If you can measure the flywheel, the 168 tooth one should be approx 14" diameter. the smaller is approx 12 3/4" diameter. Why all the bother? If you go with the 153 tooth flywheel and 10 1/2" clutch and pressure plate, you will not have any problems. They will fit in either size bellhousing.

Originally posted by tpshea:
Why all the bother? If you go with the 153 tooth flywheel and 10 1/2" clutch and pressure plate, you will not have any problems. They will fit in either size bellhousing. Because if he has a 168 tooth now and orders a 153 tooth flywheel/clutch set-up, his starter will not work anymore.

If it is a factory BB it should have a 168tooth unless it has been changed.

Originally posted by Epistuff:
Because if he has a 168 tooth now and orders a 153 tooth flywheel/clutch set-up, his starter will not work anymore. Oops! My mistake graemlins/clonk.gif , I have one of the new starters with two sets of holes so I can go either size. He did say it was the original starter.

Not all rats have 168 tooth flywheels. Many 427s out there with 10 1/2 setups from the factory.

Wally, the only ones I know about are the 65 Vette 425 HP 396 and any of the L-88 ZL-1 stuff.

billyb-
You can also take a look at your existing bellhousing while it is still on the car. If you have the large bellhousing than you likely have a 168T flywheel. If you do have the larger bell and you end up having the smaller flyheel after you pull itapart, don't worry because you will be able to fit a larger 168T flywheel in that bellhousing. I will send you a picture with a large bell and a small bell next to each other so you can tell them apart.
The large bell (168T) has a "bubble" shaped pocket for the starter and the samll bell (153T)does not have this "bubble".
Check your email for the picture.

Even more certain, just look on the side of the bellhousing right above where the starter is. Large housing number ends in 621 (for the stock GM aluminum housing of course).