I had a rebuilt 350 put in my 85 trans am 305 cc quad. and 700r4 . It is a basic 350 not anythin real souped up . I wasnt expecting to light up the tires with it but from dead stop floored im lucky if i can even spin the tires y is that ??? .When im going like 20 mph it kicks down pritty good when floored so i dont think its my tranny . my old 305 seemed to be able to spin the tires pritty well and those things stock had like no hp ha . The mods i had done with the rebuilt 350 are headers w/ full custom 3 inch magnaflow exhuast with duel snorkle cold air intake . car runs good had a tune up done recently so idk what it could be .

 

"Lighting tires" is only a sign of loss of traction, not power. Is the 350 faster? It should be, but maybe not noticeably - depends on the heads, cam, intake, etc. There were many 350's that only produced 145hp (less than a 305) in stock form - just throwing any old 350 in there could be a step backwards. A stock 350 doesn't 'loose traction' any easier than a 305.

Your rear gears are killing you too - you probably have 2.73 peg leg in a 305 auto car.

 

I agree with camaronewbie. The rear end is killing any gains you got from the new engine. There is a lot more to this than putting in a new motor. If the engine pulls well from a dead stop then you need to look into getting the rear end upgraded like a posi with 3.27 gears or something like that. But if the engine bogs then you may need to recheck timing,no matter that you just had or did a tune up. Either way a new rear end will help a LOT

 

i do have posi rear end with 3 23 gears . i beleive at least thats what i was told . i know it is posi for sure though from spinning the tires while car is rasied . it doesnt really bog on me id say just doesnt kick in to great takes like an extra second to rev up past 10 mph . the thing does feel fast after the initial dead stop floored however. like lets says i floor it at 20mph it kicks down good and seems fast to me im sure its not anywhere close to 400 hp but still . i have a 2000 cadillac eldorado 4.6 275 hp and i know my trans am is faster but they both are about the same from dead stop id say same amount of tire tractions lost . i know its not a great comparision between the 2 cars . like you guys said i do beleive it is possible my 350 just isnt made for racing . i just wish i knew for sure that there wasnt some problem cuz like i said it does feel pritty fast after the begining acceleration .

 

Maybe you need a higher stall, to bring the rpm's up a little. If you know what cam is in it that will tell you a lot ( lift, duration ect....). Different durations as timed @050 (in most cases over 225 degrees) need a higher than stock stall converter. So if you have to get over 10 mph before you see the power kick in you may need one. But that is just my opinion. Not all 3rd gens are made for racing you have to do that yourself. Is that what you want? Because there are so many cam's out there that finding the right one that will work with the heads and fuel system you have is kinda easy, you just need to deside what you want the car to do.

 

I should also add that bone stck 700r4 trannys are not known for big street preformance. So add that to the mix ang engine gains wont show up as much untill as you see, you are rolling then nail it.

 

i had another question about my transmsion . seems like when i mash it when driving 10 to 60ish its pritty good kicks down hard rpms go way up but when i get to bout 65 mph the car shifts and the rpms and power is lost alittle . is that how 700r4s are ??

 

Yes. Because when you nail it, it down shifts, and when you let back off the gas it shifts back into overdrive, so the rpms fall back down. Thats normal.