jerod187

Hey guys me and my dad just pulled out the rear end out and we got the posi axles, clutch packs and all that out and cleaned everything up and my rear end is the 28 splines with the spider gears and i think the stock gears were 3.08s if i did the right math and i wanna put 4.10 gears in but i was told you cant put those in the stock posi??

also what would you reccomend for a stiff clutch pack and certain brands or just a extra shim?

mjr46

get the carbon fiber ford racing clutch pack kit and yes you can put 4.10 gears in, I just did it a few weeks ago for a member on here....as long as you know the proper procedure to follow when installing gears, your fine, don't know who told you that you can't put 4.10's in??

jerod187

Ok ill get those clutchs and it was a guy at a palce called lake performance and ya he said like the gear is to big when you go to 4.10s so you need like a eaton or auburn posi well thats what he told my dad anyways,,,

how much of a difference u think ill notice with the 4.10s? also i have some 69 heads that have 1.6 and like 1.9 valves and theyre all ported and flow benched and new valves with stiffer springs and a holley cam and gt 40 intake with full echaust what size injectors should i run? i ahve the stock ones right now

mjr46

the 4 .10's will be a huge improvement and yes you can install them on a factory unit, I'd use the ford racing ones as they are user install friendly.....as for the injectors, with that mild set up you should be able to get away with stock injectors for now, best thing to do is assemble it all then have it run on a dyno with the a/f monitored at all rpm levels to see if it goes lean under heavy load, if it does and you have FP set to optimal setting and proper fuel pump then you'll know the duty cycle of the inj are maxed and at that point it'd be reccommended to upgrade and at most with your set up to 24's would be my guess

jerod187

ok sounds good and my buddys has the a/f sensor thing and at idle it was like 53 then at like 3k it was like 30 then at 4 it was right around 15-16

Portmaster

Someone should have told me you couldnt install the 4:10s. I screwed up and did maybe a few hundred, lol

jerod187

lol ya eh well i guess that guy was just a damn idiot then!!

Alex-7

Or he really wanted to sell you a new posi

Hamutoff

I believe that you can fit up to 4.30:1 without modifications, someone please correct me

mustang-101

actually they should fit i would say if anything the axles would have to be changed