Im thinkin about converting my six cylinder to a 350 crate engine with 260 hp my rear end has 3.42 gears i wanna put a turbo 350 with a ratchet .just wondering where my rpms a be at cruising down the highway at 65 could stick with my five speed but i have not made my mind up

 

direct drive 3rd gear, 3.42 gears = 3,420 rpms at 60 mph, so roughly 3500-3550 at 65 mph

 

That would not be good at the gas pump

 

Not good on the motor, either.

 

I will probably just stick with my five speed

 

yea, it is a little rough on the motor, tends to burn the rings out sooner. ive ridden in cars that had 4.10 gears and no overdrive, 5k at 75 mph is no fun on the ears or wallet

 

I had a s10 with a 327 and turbo 350 and now that i think about it i got like five to the gallon on the highway and the guy i sold it to said he got 9-10 driving it around town

 

i just put a 3.73 rear end in to my 305 maro an with the 700r4 when im cruising around 70 mph my tach says around 2300-2600 rpm with tc locked

 

There's no way of knowing what you're exact final drive rpm's would be without knowing the diameter of your rear tires.

 

Back has p255 60 15 front is p215 60 15 im probably just gonna change the bell housing on my t5 and use it when i change the motor.