What gear for a TH350

[cmegga]

Im just trying to make sure it wont be too too ruff on the highway. But the damage is done , I dropped her off for the job this morning.

I should see here back Thursday or Friday, Ill let you all know how it worked out, and what RPM I actually wound up with on the Hwy

 

[MaineShark]

If 2.81:1 is giving you 2600 rpms, then 3.54:1 will give you 3275 rpms.

Take the new ratio (3.54), divide by the current ratio (2.81), then multiply the result by the current revs (2600). The result will be the revs with the new ratio.

I'm curious, though. At 70, with 3.55:1 rear gears and stock tires, I turn 3000 rpms. Does your car have a different tire size than mine (255-60R15)?

Joe

 

[cruisin-davey-g]

If 2.81:1 is giving you 2600 rpms, then 3.54:1 will give you 3275 rpms.

Take the new ratio (3.54), divide by the current ratio (2.81), then multiply the result by the current revs (2600). The result will be the revs with the new ratio.

I'm curious, though. At 70, with 3.55:1 rear gears and stock tires, I turn 3000 rpms. Does your car have a different tire size than mine (255-60R15)?

Joe

Yeah, Joe..........Tire size does make a difference in overall gearing. I'm curious too as to what size "cmegga" is running.

Dave

 

[cmegga]

I am running 255-60-15 tires, I had to measre them to get a ruff estimate on RPMS and they stood just a hair over 26'' tall.


The only other factor that may be throwing things off here is I had a custome made stall converter when I did the engine rebuild. It was set to connect ruffly at 2300 rpm.

Then again who knows how accurate my 22 year old tach is.

Also everthing here has been estimates , excpet my current situation 2:81 turning 2600 RMP a 70 MPH.

We will know shortly , the rear end is out and I should have it back in a few days now.