Hey guys I'm doing my 5.3 T56 install in my 69 and I have not done the exhaust yet . was going to use the stock manifolds. I just got a lead on some full length ls headers from a truck. Any ideas if they will work or not. Just curious

The problem with our 1st gen is the drivers side steering box. Almost every manifold or header hits it unless it is designed for our cars. Truck if I recall does not fit drivers side. Fbody does but the engine cannot be too far forward.
What oil pan are you using?
How far is you pass head from fire wall?