Right now i have 3.42 gears that runs 3000 rpms with a 275/60r15 tire at 70mph. What are you guys RPM's? I plan on a trip to the beach this summer that is 4hours away this sounds like a bit much for that long will it be ok?

your trip should be fine ran the original 305 in my car at almost 4000 rpms for two hours temp never went above 180 and only burned about 5 gallons of gas, just check your oil and coolant levels and have fun. What beach you goin to?? Oh and i run abour 65 at 3500

<font face="Arial,Verdana" size="2">Originally posted by Loki:
Oh and i run abour 65 at 3500 </font>

Same here, I have 4.10's with the same size tire. The nearest cruise from where i live is an hour away. I bought my car to drive it. Just keep tabs on your fluids.

305 4-speed, 3.42 posi rear, stock size tires -
I turn 2,500 rpms at 65mph. Drove it from Maryland to Maine 2 years ago - pretty much 10 hours straight driving. No problems! http://www.nastyz28.com/ubb/smile.gif

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A's Z
1981 Z28 - Original owner
Numbers matching
305, 4-speed, hardtop

Seems kinda high for a 3.42 rear with such a large dia tire. I have 4.10's, 255/60R15 tires and only turn 3500 @ 65 mph, I would think your rpms should be a bit lower since you have a taller tire and lower gear.

thanks for all your replys gonna go to myrtle beach this summer several times and i wanna have the tops out just want to make sure im gonna get there and back.

converter if auto makes a big difference a 3.42 with 2,000 stall is hywy freindly with 3,000 stall its more of use the hywy when you have to, any more stall and you wont hit the hywy, i just put 3.42's in my car a couple months ago and 60-70 was 3,000rpm's with a 3,000 stall

Factory 3.73 rear with stock R70 15" wheels. I turn almost exactly 3,000 rpm at 60 mph. The car always cruises fine at that speed and rpm, never a problem.

Fwiw, my 1967 SS/RS car when new ran 70mph at about 3050 to 3070 rpm with my M-20, 3.31 gears and D-70/14's at about 25.3 to 25.5" tall. (And she would run above 130mph easy!)....

Good enough for GM, good enough for me!! That's why I like my 3.31 gears!!!!!

pdq67

I was turnin 4000 at 80+ behind "Goat" on I-95 goin to the track.