4 OR 5 speed

[tom406]

No right or wrong answers here, obviously. I personally hate driving cars without overdrive that have steeper gears than 3.50 or so. I had 4.11's in a Mustang a while back, and it sang at like 3500 rpms on the highway at 60mph. Very tiresome. I did a World Class T5 (2.95 1st, .59 or so OD -IIRC) 5 speed swap and loved it. I left the 4.11's, but even with an aluminum flywheel, 1st gear was pretty useless, and 2nd gear starts were no problem. If I had kept it, I would have done 3.50 gears and I think it would have been perfect.

Kiesler seems the best for these conversions, as they were the first to really tackle the engineering side of these things:

http://www.keislerauto.com/gm/chevelle-gen2-kits.html

If you want to keep your 4.10's, I'd go with the TKO600 highway OD model for sure. With a TKO500 and that steep 3.27 first gear, you'll probably want to go back to 3.55's or maybe even 3.23's if its quarter mile days are over.

If that audio track has made you want the Muncie, then by all means go for the wide ratio M20-geared unit. That 2.20 M21/M22 1st gear is just so high. (In '63 Bill Jenkins used Ford T-10 2.36 first gears instead of Chevy 2.20 gears in his 409/Z11 race cars for an advantage.) I much preferred the M20 in my RS Z28 over the M21 in my first Z. But the 5 speeds I've had were by far my favorites overall.

Just my $.02.....