yeah the 9in isnt really needed unless your gona start puttin down some power. but i mean, if he wants to start building the motor, i say do that last, do drive terrain and tranny first. my point of view is why spend money on the 8in? you can get a good 9in, housing, third member, gaskets, bolts and seals for a little over 1K. thats really not that bad. i would just go for the 9in and not have to worry about the rearend anymore, just move on to another part of the car. if hes serious about modding the car and performance, get the 9in. thats just my opinion, its his money though.

 

What is the power level cutoff for an 8" rear end? What is "puttin down some power"? 300HP?

 

hmm, im gona say about 400hp, then i think its time to start thinkin about a new rearend. but one day i hope to get a blower , thats when the 9in will come in handy
but if your askin how much hp does it take to snap a 8in, then i dont know

 

I be honest, I really don't know when the average breaking point for an 8" is. I do know that when it comes to breaking differential parts, what matters most is how it's driven.

In this case, I wouldn't buy the 9" until you're sure you need it. Or if you can get it really cheap.

 

I've heard the 8" are good for around 500hp, whether or not that's true I don't know. But in all liklihood you'll break a 302 block before you break an 8". The 9" is the way to go for any type of performance if for no other reason than parts availability. The 9" is the most popular rear end(for Chevy and Dodge as well, though to a somewhat lesser extent than Fords, duh) for performance solid axle setups, and the availability of parts, and especially gear ratios is excellent. Finding good quality parts for a 9" for performance at a decent price is pretty easy

 

I was going to beef my 8" up - am seriously considering the attached withTrue-Trac clutch less posi & 3.4 gears. Currently running 302 with 4v Holley, 289 performer intake, and hookers. Am planningon dropping in a ford racing 302 at later date. Should get to 350 HP and from what I heard the 8" would be fine for that.

I'm sure their are cheaper/better alternatives but putting in new 3rd member would not be too difficult for me. Swapping out whole rear end may be past my skill set and would end up costing me more if I have to have someone else do the wrenching.
http://cgi.ebay.com/ebaymotors/ws/eB...178&rd=1,1

 

I think you need to start 'listening' in better places.

I've broken a 9 inch when my motor was running 330 hp to the back tire through an auto with only drag radials.

There are two ways to build anything, the right way and the multiple times way.

The question I asked previously has never been answered; is this rear wheel or flywheel horsepower you wish to build for. If you want 300 at the back tire, you should upgrade your rear to a 9 inch. You should also do a load of other changes to the car to support that power level. Many people seem to forget that the HP ratings all these cars had back in the day was not the same rating as cars have today. We have a hopped up 289 that is a decent performing street car 65 coupe. It makes 180 RWHP. That's cam, head work, intake, k code manifolds, toploader and an 8 inch and no power accesories.

 

how do you make a 73 302 get more than the 173 horsepower that it comes stock with? Is this weak horsepower rating because of the less than par internals?
(pistons, cams, etc) i know its a product of the gas crisis and emissions, is it worth building? ie (edelbrock package or something close to it)

 

in responce to the gt40 heads being the same...

http://www.stangpro.com/html/article...les/gt40p1.htm

 

theoretically, all work better than standard manifolds
tri-y will give better mid range scavenging (= streetable torque) and long tubes outperform them once you get to the top of the rev range (which is why drag racers prefer longtubes)
tri-y will usually give better ground clearance and easier to fit.
shortys are supposed to be a compromise for lack of space.