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I am a brand new first time Camaro owner. Just bought an 86 IROC Z that the previous owner had modified to the following state:
Blueprint 383 stroker (dyno that came with engine had about 420hp @4800-ish rpm), Holly 750 double pumper; TH350 Trans with b&m megashifter; Brodox aluminum heads (no specs given), steel crankshaft; ceramic short pipe headers, Mufflex 4" exhaust, Spin Tech mufflers, Hughes torque converter (2500 stall), 10 bolt positraction with 3.73 gears, Spohn Performance lower control arms and subframe connectors, and Jegs torque arm.
To be up front, I am far from a gear head. I don't know a ton about cars. So I am looking to get some proper advice/suggestions/ help/ direction from you guys that are.
I am generally going to be using this for the street. I don't plan on taking it to the track (though obviously that could change down the road I suppose). I'd like to be able to cruise around in it, but also be able to hit the gas and have some fun in it if the occasion arises.
I am thinking about upgrading the cam, and downsizing the exhaust a little bit (sounds decent now, but seems like overkill).
So here are my questions: Have been told that the TH350 can't handle much more than what the engine is currently putting out (420 based on the engine dyno from Blueprint). If I change the cam to something bigger (or add power in other ways, should I get the tranny built to sustain 500hp (even though I'm really only looking to get to about 450ish) that way I know I won't have any issues?
Gas mileage is currently pretty terrible, and have been told I probably don't want to be taking it onto the highways. Should I be looking at taking the gears down to 3.5s or 3.4s to make it more street friendly? If I do that is it going to totally kill the fun when I hit the gas? (Also should state that I'm not a big burnout guy, so not likely to be wanting to long burnouts, etc)
If I add power, but then take the gear ratios down to 3.5s or 3.4s, am I going to blow up the rear end if I put my foot in the gas?
Have been told that the TH350 can't handle much more
Not true.
Gas mileage is currently pretty terrible
That is DIRECTLY BECAUSE OF the Turbo 350. It has no overdrive. The correct transmission for the car did have that. The stall doesn't help that; under lots of normal driving conditions, it's not hooked up, and therefore the engine's power is going into heat in the trans fluid, rather than pushing the car around.
am I going to blow up the rear end
No one can say. The rears in these cars are kinda fragile, this is true; but, the things that kill them, are SHOCK loading (big clutch dumps for example), coupled with TRACTION.
Without knowing what cam is in it, it's hard to say what gains might be available by changing it. Might already be too much, who knows. Almost 100% for certain though, if you cam it up, the gas mileage will get worse.
My first recommendation would be to replace the 350 with a 700-R4. Leave the engine and gears alone. Same stall speed converter should do just fine. Then go from there. I also agree about the exhaust; that kind of muffler (I use the word loosely) isn't very effective at dealing with the noise. Good for max power maybe, but not much else. Might want to consider simply adding a resonator in each tailpipe to start with.
My first recommendation would be to replace the 350 with a 700-R4. Leave the engine and gears alone. Same stall speed converter should do just fine. Then go from there. I also agree about the exhaust; that kind of muffler (I use the word loosely) isn't very effective at dealing with the noise. Good for max power maybe, but not much else. Might want to consider simply adding a resonator in each tailpipe to start with.
Am I wrong to assume that the stock 700-R4 won't take the 450-500hp that I'm looking at getting the car to, and should just have it built up right away?
Am I wrong to assume that the stock 700-R4 won't take the 450-500hp that I'm looking at getting the car to, and should just have it built up right away?
Neither a THM350 or THM700-R4 "Stock" will handle 450-500 HP reliably...
However both Transmissions can be built to surpass that range/ power level.
I have been building THM700-R4 Transmissions and 4L60E Transmissions for up to 1,200 HP (with a warranty) for 8 years now.
So 500 HP is very doable.
I personally do not offer services to the Members here...
However, I do work with a Business here that does offer services to the Members on the Forum.
The name is Pro-Built Automatics; its a one-man shop but is excellent. The owners name is Dana.
His user name here is: "Pro Built Automatics".
His website is: probuiltautomatics.com
His Phone number is: 909-435-5360
Leave him a message is he does not answer... he will call you back... like I said he is a one-man business.
