load1234

help! i need some pointers on tuning my 86 gt. i recently changed from efi to a 650 holley doublepumper on a rpm air gap intake. it has a 6AL box with a probillet distro. i didnt change the heads but i was wondering if i should have. i dont know if there is really any difference in the efi heads compared to the carbed heads from the earlier cars. also, i put a 85 fuel pump in to reduce the fuel pressure. any help would be great

mattdel

i missed the question...

load1234

i forgot to mention that the carb has 67 jets in the front and 69 jets in the back. the question is, do i need to change the heads? also, it idles fine but when i put my foot into it, it bogs down, then picks up like its getting too much fuel still. sorry i suck at posting things. anyone else with this setup?

Venomantidote95

it would have been cheaper for a MAF conversion! It probably is getting too much fuel, what kind of regulator do you have now and what is the pressure?

jwog666

what else have you done to the engine? if all you did was rip off the efi and bolt on a double pumper the bog is most likely being caused by the massive ammount of fuel being pumped in by the twin accelerator pumps. on an engine with little to no mods, and low hp a double pumper is overkill and will require alot of tuning to get running properly.
changing heads alone wont help much, but heads, cam, lower gears and/or higher stall converter combined would.

load1234

thanks for the help, i have really only done the top half. i changed the mechanical advance springs in the distributor to the lightest and that has helped mostly. just trying to fine tune it now.

mjr46

5 spd or auto tranny??

load1234

5 speed with 3.55 rearend

Venomantidote95

Uh oh not 3.55`s put some 4.10`s in there and she`ll be fixed LMFAO! Sorry sorry back on topic!

load1234

well, the gears were free and the install was a case of beer so those 355s were a steal. put a set of early heads and seems to help out some