I am having the hardest time with this one. Ok here it is... about 2 years ago I bought an 86 firebird SE. It came with a 305 that had a computer controlled quadrajet. the car only had 116,000 miles on it which isn't bad and it ran fine untill I got a hold of it. The engine always ran fine until I stomped the gas and it haul a$$ to about 3500 rpm and then it would start bogging REAL bad. well after about 7 months I started replacing things. Eventually (because I somehow ripped the harmonic balancer off and snapped the crank) I replaced the engine with a GM crate 350 LM-1 engine. I put on it a new fuel pump, water pump, alternator, edelbrock performer carb (600cfm), edelbrock performer rpm intake, new distributor with vacuum advance, new cap and rotor, new hei coil( 50k volt), new accel superstock wires, and a crane wolverine cam with 465 lift 290 adv dur. 220 intake and exhaust. I put shorty headers on it with true dual exhaust back to dual 2 chamber flowmasters with turn downs before the rear end. With this and the 3.73 rear end I ran a 9.4 and 77 mph in the 1/8th. BUT...my bogging problem has come back to haunt me.............and eventually it will make me go insane! Now for details on the problem. Usually it does it only when the engine is warmer than 190. It will bog real bad and start making funny noises when I stomp it. When I popped the hood with the engine still running the fuel filter was only half full and the gas in it had a LOT of air bubbles in it. At first I thought that I was vapor lock so I ripped my carbon canister out. That didn't work. Next I took the ventilator cap off and cleaned it and made sure it worked. This helped somewhat and took care of the sucking noise that happened everytime I pulled the gas cap off. but the other day it came back. That all too familiar BOG FROM HELL. I am going crazy trying to figure this out. Can someone please help me

 

hey man i bet its that your vapor lock and your hedders are too close to your fuel lines..

hope this helps