Hi all,

This is my first year out with my restored 67 GTO.  It has a 400 modified to a 478 stroker that puts it over 500 hp but when I drive it feels like I'm driving my grandma's 30 year old buick.  It has little pep off the line like it should with such a motor.  I've asked a friend who knows cars and he told me it could be the torque convert stall not working properly, the rebuilt tranny could maybe not have been done with special high performance parts or the rear end needs to be redone.  I've cleaned out the stock rear and the torque converter is new and has a 3000 stall and it's not like the rear is burning our from being poorly rebuilt.  I'm just wondering if any of you had a similar experience and could give advice on where to start first so I can get this fixed and feel the power of that engine like I really should.

Thanks,

JT

I would start with the basics. I would check the timing and make sure it's within either stock specs, or your engine builders recommended spec. Next, could the engine be way too lean or way too rich. You can adjust the carburetor accordingly. Check for vacuum leaks or unplugged hoses or ports on the carb or intake manifold. 

 

If none of that helps, pull your spark plugs, they usually have a story to tell.