Thread: help

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need help on this one(many more) ,i have a 454 chevy with a 270h magnum cam with springs ,lifters(hyd)etc ,750cfm holly ,wieland stealth manifold,headers ,and a msd 6al and one of there distributors and a double roller timing chain backed with a 700r4 with a shift kit, what would be the best convertor to use ,and rear gears on the way to the back of the car? also does any one, might know what kind of muffler"s would give a strong sound to complement that big block and cam, and would i be able to use that set up for street/strip and not look like a fool? this engine was a tire burner when it was stock,don"t know what to expect now, i don"t know what rim and tire set up would work. i got alot done on my own so far all the way up to the engine and ladder bar set up, but i just went flat please some one help out with there advice

A 3.55 rear gear with the 3.06 first gear of the 700R4 will give you a final drive in first gear of 10.86, or about the same as running a TH350 trans with a 4.30 rear gear. The final drive in fourth gear with a 3.55 rear gear will be 2.48 and should offer very low engine rpm's on the freeway, depending on tire circumference.

The biggest bugaboo in the 700R4 is the second gear ratio, which drops from a first gear ratio of 3.06 all the way to 1.63, so be prepared for the car to fall on its face on the 1-2 shift.

I think Comp is fibbing a little with their description of the operating range of your cam from 1,500 to 5,800. That's an operating range of 4,300 rpm's. Cams are generally efficient in a range of about 3,500 rpm's and looking at similar cams from other grinders, I'd bet the true operating range is more like 2,000 to 5,500. They are saying you can run a stock converter with the cam, but I don't think it would work out as effectively as a converter that's a little looser. I wouldn't go wild on the converter, because of the low first gear ratio, but I might go for a converter in the 1,800-2,000 stall range just to keep the motor from trying to creep on the brakes at stoplights. Use a nice big transmission cooler in front of the radiator and plug off the OEM trans cooler lines in the bottom of the radiator.

With a 10.86 first gear final drive, the motor will try to tear the tires off the car, then will lay down in second somewhat with the 5.78 second gear final drive.

As far as mufflers, who knows??? It's like I said in another post, I saw a dyno shootout of several different kinds of mufflers several years ago and there wasn't 5 hp difference between them. As far as sound, I personally feel that two 36" glasspacks can't be beat.