Yeah C5 ('97 to '04) and C6 ('05 to ?)'vettes use completely different stuff. I think the switch to ZF was '89 or '90. Earlier C4s with manual transmissions are the 4+3 like my '85.
The 4+3 is something like .68 in 4th and over. I understand the ZF guys actually get top speed running in 5th but best economy running 6th. I've never driven one.
I once owned a Saginaw 4-speed with an OD adapted from a 3-speed. I was going to put it in my Suburban until I called Patricks and asked if their shifter would work on it. The answer was no, then yes, but with modifications.
I ran a modified shifter with the OD Saginaw when it was in an F-body in the 70's and didn't want to play that game again.
My preference would be to run a 4+3 in a truck before I'd try the modified Saginaw route or the ZF either one. But running a mild six like I've currently got in my Suburban a T-5 seems the best option.
If I ever get around to changing it.
The 4+3 'vette will get 25 mpg driving on the highway driving pretty agressively. I don't think the ZF guys do any better.
