I have a 86 z28 camaro lets say has 300hp engine with a rpm range of 2000-6000 its an 1/8 mile drag car now i have a built 700R4 transmission built for 500hp so its strong and it even has a (cant remember the name of it) its out of a corvette to make it shift hard, but anyway it shifts good and no i am going to be swaping that transmission out for a turbo 350 transmission, i do a 9.1 1/8 mile with a 2.1 60ft and i have a 3.73 rear diff gear ratio what kind of diffrence should i expect with the turbo 350 transmission?

 

If you had 300 hp you should be turning in the 8s and that 60ft should be under 2sec unless you have a traction issue. I don't think your built 700r4 is holding you back. What about your torque converter?

 

I agree. You need to focus on traction next. Swapping transmissions won't make much if any difference.

 

The th-350 trans may slow you down due to the gearing.

The th-350 has
1) 2.52
2) 1.52
3) 1.00

700r4 has
1) 3.06
2) 1.62
3) 1.00
4) 0.70

Traction is your issue, and maybe torque converter stall speed. Not the transmission

 

I have no traction issiues but once i shift into second gear its like i hit the breaks

 

I dint have an traction issue and i know the transmission isnt holding me back i was wondering what the diffrence would be with the turbo350 trans because of the gear ratios

 

The 700R4 does has a big jump in gearing from first to second compared to the Turbo350, but I can't see it improving your times any. If traction is not an issue then I would look into a better torque converter, not sure if you have an aftermarket one or stock.

 

Something is off, and it's not just the transmission.

300 HP should have you around 8.5 1/8 mile, your 60' times are slow as well.

If it's not a traction prob then it's a torque converter or engine power/torque prob.

 

You need a lower rear end gear for your amount of power.

When I swapped my 3:70s out for 4:10s and upped from a 2500 to a 3200 stall with similar power levels as yours, it gained .2 on the 60' and shaved about .3 off the 1/8th time. You need the lower rear end gear to help you pull the long second gear as you don't have the power.

 

I found out that actually it could be my ignition thats holding me back and ive talk to someone that knows and says that should drop me if i get a nice 300$ ignition

 

That depends on your ignition setup right now.
I agree that the th350 swap would not be worth it and wont prove anything.

 

Ignition system is not your prob. At your level a simply HEI dist. will work perfect. I ran down to 11.40's @ 118 1/4 mile with a stock HEI dist. that I added a recurve kit to. I shifted at 6400 rpm.

You don't need a fancy ignition on a mild engine. They are not needed until you get into high RPM (7000 and up), boost, or nitrous

 

My stall converter is actually a stock one from an older corvette which i think is like 2200 or something and actually as im swapping this transmission im also going to be getting a 3000rpm stall converter