i currently have 2.93 posi rear end in my 82 t/a.
My friend has a borg warner 3.55 posi disc brake rear end for $300.
I know I want it but how much will it acceleration and lets say I leave the traps at about 90mph...how high will i be reving..that is my main concern .
Also a 60km/h cruise in third would rev at what with those gears.

Tranny is 350 non lockup w/2400 stall
sbc 350 bored 0.030
xe262 cam
rpm airgap
4150 650 holley

thanks for input

 

I really dont know,but I would get the rear if I were you. If you dont like where your revving once you leave the traps you can always use a bigger tire. Good Luck.

 

ya I heard about going for a taller tire.
But would the acceleration benefits of the 3.55 ratio still be present?



but I will look into taller tires
thanks for the reply

 

It defenetly should be. I would be running at least 3.42 gears with that XE262 cam. I think youll be happy with the 3.55's. Good Luck.

 

Need your tires diameter to calculate engine rpm. Go to this sight for a nice RPM to Gear calculator:

http://www.csgnetwork.com/multirpmcalc.html


Tons and tons of different calculators at this site:

http://www.csgnetwork.com/automotiveconverters.html

Edit: Assuming a tire size of 25.7" ( 245\50x16 ) with 3.55 gears you would be turning 1860 RPM at 60KPH ( 40 MPH)

http://www.csgnetwork.com/gearratcalc.html

 

Just out of curiosity where did you get those hp and tq numbers in your sig?and is that at the fly or the wheels?(I assume flywheel). I am just curious because Super Chevy built almost your exact same motor in one of their Danger mouse segiments and they came up with 386hp and 438tq. Which is alot more power even though they have a better carb and probably a more freely flowing exhuast.

 

really! a magazine built a setup sort of like mine.
Thats awesome..too bad i didnt read that article

but yeah that is with the wrong carb ...this thursday Im gettin that juicy 4150 650cfm holley

those #'s where found from my resent dyno visit.
THose are estimated @ crank numbers based on rwhp and a 25% drivetrain loss.
Exact rwhp = 247.9hp@5100rpm
Exact rwtrq = 263.1@4800 *I didnt go over 5100rpm because I was a little worrried because the bottom end is quite fresh*
There was almost no tuning done that day on the dyno with those numbers but I will give ya'll a response on friday on how the dyno run was.
Hopefully I will produce similar results to the Super Chevy build up.
Thanks c ya then

 

Those still sound like some good numbers. Do you have any track times yet? let us know when you get new numbers for that thing. Good Luck.