Hello all!, I was wondering what size rear end my 66 coupe has in it. It's the original 289 auto and the original diff. Is it a 9 in. or 8 in. I believe it's a 9 in. but just wanted to make sure. The 2nd question is what do you have to do to replace the cowl seal. I saw Soaring say you had to drill out 70 rivets or something. [:@] Lord i do not need to do that, but if that is what is leaking then it needs to be done because it's rusting my passenger floor pan. Thank you!

 

To my knowledge, the 65-66 V8's had 8.8' 's.

 

If it's the original rear, it should be an 8". I believe only the "K" code cars came with 9's. The 8.8 was not in production in the 60's.

 

Oh.. Shows how much I know.

 

Yeah, it's an 8" rear. There are over 100 spot welds you have to drill out to get the cowl out. Or, you could just put a cowl cover on it until you get the time to replace the cowl.

 

Just look at it from the rear...an 8" is a smooth half sphere shape, the 9" has an extra bulge for the ring gear IIRC.

 

Remember that many sections of these little cars were done by people rather than machines, and what's true on one may be different on anoher. I've seen close to 200 spot welds holding the cowl together. And be prepared to go through several drill bits.

 

I believe NPD sells a special drill bit for just that, don't they Dan?

 

I know some of the parts vendors do; but from what I understand, it's also the type of thing you can find at a home improvement center. I helped a buddy with his a few years ago, and he had resorted to a standard drill bit over the special one. I'm not sure if it was due to costs or simply how well one worked over the other though.

 

Ok, Thanks. So i have a 8 in, rear end. Cool. Man, that is alot of work for the cowl. I may just put a cover on it....... but i still dont know for sure if that is what is leaking. How can i check to see if it is the cowl seal? It's only leaking on the passenger side. Thanks for all your help!