Hello, I am planning on swapping my 302 out for a 347 in the near future and was wondering what additional/supporting upgrades I should be looking at doing to the car? The car is a 74 Comet GT with a T5 and the engine should be around 400 hp. I'm going to switch to a hydraulic clutch setup at the same time I am doing the engine. I want to put in subframe connectors, is there a good kit out there that would not require cutting into the floor? I am not sure how much the current rear end can handle so my plan was to run it until it breaks, then go to a 9". Thanks
"You" will be the deciding factor between the 8" and stock T5 living or dying with a 347. You already realize both are marginal in this application. I used Chassis Engineering subframe connectors on my 74 Maverick and they fit well with a little trimming.
Hey Cloontang: You should be okay with the 8" incher as long as you don't run ' Slicks ' . If you're going for a neat-street version with a 347 stay with a good street tire. These cars don't weigh much and that helps out . We're running 3:55's on a few cars here with Trac-Lok and a Currie Setup and they seem to hold up well. Just my opinion. Cometized (Chip)
Ok thanks, I'll look in to them. Transmission is a TKO500 with less than 10,000 miles on it so it better hold up! haha
That's good news I was under the impression that the 8" would be a major weak point. I am not planning on running slicks either. What is involved with getting the Trac-Lok and Currie Setup? Is it just different internals with the same axles and everything else?
Yes, the TKO500 is MUCH better than a stock T5! I've had two of those and one TKO 600 in 10 second 1/4 mile Foxbodies and they held up very well!
I bent two driver side axles in my 8" with my 347. they were bent on street tires. I have Strange axles now w/Detroit locker and 3:55 gears, small maverick drive shaft. ...
You must have ' hooked-up ' pretty good ! Did you have the ' locker ' in place when you bent them ? Or did you add that later on ? Chip
The pinions are the weakest points on these rearends. As the ratio increase it becomes way too thin. Put a set of sticky tires under decent power with a clutch drop and pop goes the weasel. Otherwise I've seen them living in street cars with more than 500 horsepower. Longevity all comes down to how hard.. and how abruptly(this shock is what most often breaks them).. you are transferring the energy to the pavement.
A lot depends on how you ' intend ' to DRIVE it ! If you burn out at every stop-light then I would say go for the NINE INCH .. If you drive it normally ( get on it now and then ) you should be OK with the 8" incher. At any rate GOOD LUCK with your launchings ! Cometized (Chip)
Burnouts are no problemo. It's when the tires quit spinning that you have to start worrying more. I've tested and ridden in test cars many tests through the test years. Sometimes it seems like my whole life has been one big long test. I know I've bought well past my fair share of rear tires. lol
I don't think the TKO will fit with out clearance from the tunnel. Another option for the rear is an 8.8 from an explorer. You will just need to take a couple inches off from one side to center it. They come with disc, limited slip and are 31 spline. Junkyards are plentiful and should be 3-400.