So I pulled the cover plate off the rear end of my 75 a couple weeks ago and saw that it had the 3.08 gears. I want a little lower gear ratio so i ordered a set of 3.73s. Im going to put them in this week. I think those gears along with my powerglide and 383 stroker is going to scoot that car along pretty good. Im excited about getting these new gears in now all i need is a locking diff, so if anybody has a detroit locker or eaton posi for an 8.5" rear end they would like to sell let me know.

 

Hope you're going to wait for the posi or locker before putting the gears in!

 

3.73's r real nice just got those in my 81, depending on ur driving style i recomend geting the posi not the detroit locker it'll be brutal when cornering, but hey if u only want performance on the strip who cares right.

 

I might even go 4.11 with a glide. My Nova had 4.56s with a glide. with 26" tires leaving at 4400 rpm shifting at 7600 it would go through the lights just after the shift light came on.

 

I want to be able to drive it on the street and get the best gas mileage a 383 stroker can while being able to take it to the strip and run decent times.

And I have to get a new diff now because the center pin that holds the pinion gears in place wouldn't come out even with me using an air hammer on it for an hour and a half, so finally I just cut it out with a torch. I have another open diff from an 8.6 rear end that im going to use for now just to set back lash and get a good pattern on the gears, and i will just change the differential later because thats not really a huge deal.

 

You did remove the lock bolt first, before trying to get the shaft out?

 

Yes I did. That differential was toast anyway. It had been run out of fluid because there was like half a quart in there when i pulled the plate and the gears had a bluish tint to them which means they were overheated.

 

Gas mileage and stroker motors shouldn't be in the same sentence. Add that to a powerglide and your S.O.L. You can drive conservatively, keep your foot out of the carb. But if you get 10 MPG be happy. Thats all I get in my 85 SWB K10. Thats got a 305 w 4 barrel AND a 700r4.

 

That sucks, but I'd bet the weight has a lot to do with it. My 327 in the Austin gets nearly 16mpg on the highway with 3.73 gears and TH350. My '71 Camaro with 427 gets about 14.5mpg on the highway with 3.42 gears.
I really don't care a lot about mileage on the toys, but it is nice if they get something halfway decent.

 

The truck is around 4000#. The tune on the carb needs to be dialed in.I tried to replace all the vacuum lines and get it dialed in. 20ft of hose and I ran out. I hate emissions era Q Jets the most. The fast idle for the choke gets stuck on for some reason. It happens randomly. I don't want to jack this guys thread so if you have any ideas through them in my project thread.