Hey i have a 68 cougar with the original 8inch with 3.00 gears. im not looking to keep it original so idk if i should wait till i get the money and get 9inch or just build up the 8inch i have. im dropping a 351w without any major mods so i think it can handle it.

So help me, 8inch or 9inch?

 

for eas of use the 9inch plus it has more gears to choose from

but the 8inch might be able to hold it.

 

8" parts are pricey, but I'd imagine that it would probably be cheaper and easier to bite the bullet and just get the Posi (Trac-Loc, whatever) center for it and pop it in.

I can't see how swapping the whole rear out would be cheaper/easier, unless you have some kind of hookup.

 

they don't make many gears for the 8" ford rears they make alot of gears for the 9" its easier to find a good gear to suit your needs with the 9"

 

<---I have an 8" in my 67 mustang. I've hit it with about 500 hp and never had a problem.

As for which gears you can get....What a buch of BS. I swear, how many choices do you REALLY need? I mean, honestly, do you want 3:73's? They have 3:80's for the 8" Richmond Gear 49-0111-1 - Richmond Gear Ford Ring & Pinion Sets ...How about 3:55's? Yep...They have em Richmond Gear 49-0101-1 - Richmond Gear Ford Ring & Pinion Sets ...Ok, they don't have 4:10's....They have 4:11's. Richmond Gear 69-0064-1 - Richmond Gear Ford Ring & Pinion Sets And the gears aren't any freaking more expensive either. Ok, a couple dollard...Like FIVE!

9" 4:11's - $185
8" 4:11's - $189

9" 3:73's - $205
8" 3:80's - $195

9" 3:50's - $185
8" 3:55's - $205

So, in MY opinion, I would keep the original 8" in there. It'll hold up to anything under 500 hp, and you have just as much versatility as the 9" and the cost is about the same.

 

i need alot personally...

and i'll be straight thats what my dads answers were, he said he'd much rather have a 9 inch then a 8 inch in a car for many reasons. some of which i listed.

 

Alot of bs answers in here(from those with zero experience).

An 8" will hold plenty of power,has many gear options and is already in under your car.

 

if your refering to me i have plenty of experiance and my dad has even more, probably more then most of this forum...

bunch of smartasses in here.

 

so your 8" diff didnt hold up to a mild 351? When exactly did you break it?

 

theres a reason everyone has a 9" in there car, and i'm not just talking about ford guys......

now if you would look at my original post you would see i say it should/may be able to hold it depending on what you call mild...

i have a very mildly built 302 pumping out 460hp... so it all depend what you call mild.