did the 68 camaro 327 4 barrel (rated 275 hp) come with a 8.2 or 8.5 inch rear end, becuase I am looking fr either 3.42 or 3.55 gears depending on the size. another question; i have a th350, so what would approximately be my rpm at about 70mph with either one of those gear ratios (right now I have 2.?? gears and i know i can get a lot more out of my car getting better ratio. When i stomp on it, the tranny doesnt shift it to second until im at 50 mph and i can take it another 5mph over that if im shifting without it over revving, so i definately need better ratios. Thank you

The 8.5 inch rear was never factory installed in a first gen...only the 8.2 and the 12 bolt.

RPM depends on tire size. Calculated rpm @ 70 mph for 3.42 gears, turbo 350 trans, and a 255/60 15 tire (27.1" diam) is 2969 rpm. However, converter slippage and different tire diameters will affect the actual rpm.

For example, same combo as above with a 275/40 17 tire (25.7") works out to 3131 rpm @ 70 mph.

I believe that all the 68 non-Z cars and non-SS cars came with the 8.2" 10 bolt. I don't think you could get the 12 bolt with the 327.

My 68 has the 8.2" 10 bolt with 3.55 gears and I'm running a TH350 trans behind a 383. I'm turning 3100 RPM at 60 mph with a 26" tall tire. If you use a taller tire your RPM will be a little less, shorter it will be higher.

I don't cruise above 60 MPH for any real distance, so I can't tell you exactly what your RPM would be at 70 - I'd guess about 3800 - 4,000.

------------------
68 Camaro, 383 small block with TH350 trans. 12.4's and never trailered.

I believe that the only 327 cars that came with 12-bolts was when the L30 327ci/275hp motor was combined with a 4-speed manual transmission.

Sean

I agree with 69Musclecar. I have read that a 12-bolt came behind the L30 (327/275 horse) when backed by a 4 speed. This also gave you multileaf rear springs if what I have read is correct.

Hmm ok thank you for the information. Now i have another question then. My car was the original 327 275 horse motor, and the guy i bought it from said it is a 4 speed, and i know there was a manuel tranny in the car at one time because there is a metal plate in the floor where the shifter was. But the problem is im not sure if it was an original 4 speed car because there is no tachometer in the dash, so did 4 speeds come without tachs back then? Also i heard that just by counting the number of bolts in the rearend (i have 10) doesnt ALWAYS mean its a 10 bolt, i dont know where i heard that from and it doesnt seem reasonable, does that make sense to anyone else? Thanks for the support

OK, I knew someone would come up with a uncommon exception and prove me wrong. haha. I think that L30 option also came with 4 leaf rear springs (instead of the usual 5 leaf with the 12 bolt) and there were very few of these cars made. Please correct me if I'm wrong.

If the rear end has 10 bolts it is a 10 bolt, no exceptions to that one. On older cars though, rear ends, transmissions, and engines are usually replaced sometime in their lifetime. Don't assume you have the 8.2" rearend just because you think it is original, its an easy swap to put an 8.5" 10 bolt from a Nova or other early 70's car. The 8.2" rear end has what looks like an upside down "V" in the cover, the 8.5" rearend has more of a round shape.

Hope this article will help you out.

It is from www.camaros.org (http://www.camaros.org) (This people know their camaros.)
http://www.camaros.org/l30m20.shtml



------------------
Cars I hope to own someday-
1967/1968 L30/M20
1967 SS