hi guys i know this question is asked about 10 times every week and its all over the interenet believe me ive looked, but i really need more information for my personal plans towards the car. any ways i'm thinking about adding gears and a posi differential the detroit truetrac to be more specific to the 7.5 ford rear axle, now i have a 2002 auto with 89000 miles and its driven daily its never going to see a track and my only mods are going to be dual exhaust and bbk cai and a tune im just looking to make it a lil faster so i tought that gears would help to launch faster, now the reason that i'm going to get a truetrac is because is a solid piece and its better than a t lok, now are there any cons about this product or this mod because i've heard that in the long run the posi could hurt the engine and the transmission because it was only meant to have power to spin one wheel is this true? how about if i want to go on long trips or if i drive my car daily like i do or a lot on the freeways? or its all good? now for gears i want to go with the 3.73 i know for autos people say to go with 4.10s but like i said i don't want to race i just want my car to be a lil faster now do the gears add extra stress on the engine due to higher rpms? does this mod actually decreases the life of the engine on the long run? i ask because this is my only car and i want to get it right because i'm planning to have this car for a long time and i dont want to kill it before its due date just to make it a lil faster now any feedback will be greatly appreciated thanks guys

 

4.10s for sure. Even in the 5 speed the 4.10s are perfect. I would even go higher if I could.

 

If your not going to be doing any hard laucning or racing then go with the tlock. as far as gears I agree with Synster get 4.10s. I got 3.73s in my 5spd and I kind of wish I had more gear. The most negative effect the gears and lsd will have is at gas pump.

 

you can, 4.56's.

 

^^ with the 7.5? i thought as high as we could go was 4.10s.

 

Nope. They make 4.56's. Check DTS. Also 3.45's.

 

That's to much gear for me. they should make us some 3.90's.

 

Not gona happen now. I'm going 4.10's personally. Eventually.

 

pft 5.29s or bust.

dont get a tlok, ive blown up to many ford diffs, get the detroit true trac

 

detrot tru trac is the best, and no a t lok or posi will not hurt your engine. the trutrac only locks up the rear axle under acceleration and one wheel starts to slip. under normal turns the rear wheels can still travel their different speeds