Hey guys I have a 7.5 gm 10 bolt with a saginaw 4 speed with 2.73 gears I wanna swap them out with something better i can't decide between 3.23 or 3.42 gears. I want good acceleration but I drive the car on the highway a lot. What do you recommend. And I'm not switching the trans lol thanks again
I had a 1980 Camaro 454 with 3.36 gears and didnt like it on the highway,,,,I also had a 1967 Camaro with a 350 with 4.11 gears and I didnt mind the odd trip on the highway.The 350 engine was quite happy at 2700 rpm,the 454 always felt like you were getting ready to race
You need to provide more information on your car before you will get a decent answer. However, 3.42 vs. 3.23 is such a small difference (about 150 rpm with 29" tires) that it probably does not really matter that much.
In general, a stock 350 will cruise and get decent fuel economy at about 2400-2800 rpm on the highway. However, you will get better economy if you can drop the rpm down to about 2100-2300.
You need to take one of the online calculators and enter your tire diameter, high gear ratio (sounds likes its 1:1), and the rear end ratio you are looking at. Then decide if you like the cruise rpm.
For example: If you currently have 29" tires, you should be running about 2214 rpm at 70 mph. 3.42 gears would bring that up to about 2760, which is still fairly reasonable.
I think a good compromise gear between what you have and 411 is 373's.A good all along gear for the bottom end and decent conservative highway gear as well.
If I had an overdrive trans I would love 4.10s but since its only a 4 speed I'm thinking the 3.42 would be best with the rpm and considering I drive on the highway for my work commute. Anyone else think otherwise
My tires are 26 tall. I always thought 3.73 would be too loud on the highways with the rpm
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Hot Rod Forum
2.2M posts
175.7K members
Since 2001
A forum community dedicated to hot rod owners and enthusiasts. Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more!