76LUVStepside

[]I recently popped a head gasket on my 350tbi and decided to go ahead and have a valve job on em while they were off. Unfortunately both heads had cracks (couldnt see em but they were there), so i went ahead and changed to older style heads which were reccomended for that engine. I now have new heads, edelbrock intake, edelbrock elec. choke carb, msd 6al box, msd external hei dist and msd coil. I put new plugs in, new wires, and all that good stuff. Now here is the problem, the engine will idle just fine, but studders when you give it gas when it isnt in Park or nuetral in those 2 it revs just fine. The response is almost nil when I want it to go, it just bogs and studders and slowly gets moving.... Does anyone have any ideas to what could be the problem. Other than the plugs and wires, the ignition is the same as it was before..... Please help I need this truck to run right.. Please email chevyluvdude@yahoo.com thanks.