I tried searching but could not find exactly what I'm looking for, also not the best on the old computer here.
Wondering if anyone is running 342 gears in their z-28. I have a pretty much stock 69 Z28 with 302 bored .30 over with a 750 Edlebrock carb, stock intake, Muncie M-21 trans. I am currently running a very low gear 488's or 456's and it really screams on the highway and I am looking to make it more pleasurable for cruising with. I bought the 342's but am now worried that they will be too high and I won't have any bottom end at all, after all I don't want to get scooped by Granny on a moped at every red light, that would be a little embarrassing.
I guess I was basically wondering if anyone else on here with a 302 4 speed has these gears and how they run. Thanks a bunch in advance.

342 is a good gear for regular driving conditions.just not for racing. still takes off great burns rubber when flooring it.:beers:

You really need 3.73's b/c of your M-21 tranny like stock was back then unless 4.10's were ordered, imho!!

I ran my old junk301 with a Duntov solid lifter cam, my M-20, 3.31's and about 25.5" to 26" tall tires back then as my daily driver fine!!

I used to just roll her outta the hole and when she hit like 3,000 rpm I'd nail her and hold on all the way to 7,000 and above!!

Some guys floored them outta the hole w/ good results too..

Running the numbers using the M-21's 2.20 low 1st gear and 3.42's vs an M-20 at 2.52 1st gear and 3.31's and you will see what I mean b/c I get 8.34 to 1 ratio w/ my M-20 vs 7.56 to 1 ratio w/ your M-21 combination..

2.20 x 3.73 = 8.206 and 4.10 x 2.2 = 9.02!!

Usually we like to see right at 10 to 1 for dragging but it kill's highway driving w/o OD!!!

pdq67

Thanks for the info guys, appreciate it.

anything numerically lower than 4.56 in a 302 is a pig out of the hole in my opinion...I had 3.73 and it just isn't enough gear...I wouldn't go with a 3.42 in a 1st gen z/28...unless you don't care that it's slow