I have a 1986 Iroc that I pulled out a 305 and went 350. I kept the t-5 and its geared well with the stock 3.42 gear. The car would run like a raped ape, but spun too bad. I recently put in a posi chunk and had to get new gears because the chunk I got needed thick gears so I got 4.10. I am just wondering if anyone knows if I would get better performance from a different gear. The 4.10 seems to go through the gears quickly (45 mph in 4th gear). I would like to know if Im wasting power by having this gear. And what gear should I have. Thanks

I prefer the 3.42, worked well with my 700r4.
I think the ones behind the t56 in the other car are 2.73 or close to that. Even with that the t56 first gear feels much lower than a t5 with similar gears. Forgot what the first gear ratio is on the t56.

4.10 just demands to many rpm for me.

Whats the engine combo? 4.10 is too much gear for most small blocks out there, especially anything stock or close to stock. 3.42 is generally considered the best all-around gear for a street car with a near-stock small block.

i think the 3.27 gears are excellent for a built tpi and a built 700r4... i think the 3.42 are a tad high for my setup....

That 4.10 would be perfect if you were running a T56 but with a T5 I would go 3.42.

Thanks for the advise Ill probably go back to 3.42 it seems to give me the best bang.

I've run 2.77, 3.27 and 3.70's in my 9 bolt. I really liked the 3.27's for auto and then T5. I recently went with a 3.70 since they are about the only new gear set available for my rear. I must say that the 3.70 was the best so far. My engine is well built but still redlines at 6k. The 3.70 (or 3.73 for your 10 bolt) is a good all around set to me. Actually I wanted the 3.42 but couldn't find a new set without ordering it from Australia. I thought the 3.70 would be a little low but it's not that different from the 3.27 for everyday driving. But, the 3.70 is much better at the track. Worth around 3 tenths a second in the 1/8 mi for me. I think the lower rear is easier to get off the line with a stick shift. On the street is a different story as 1st gear has to be pedaled quite a bit to avoid massive tire spin! I don't think I hit full throttle on the street til about 5 grand in 1st.