AWAG

I blowup my old 350 in my altered and put together a new 355 and tolk it to the drag strip after making some easy passes on it I ran it all out. I could only get 6500rpm out of it then the next pass was only 6300rpm and the next pass was only 6000 and every pass I made less and less RPM . I check valve spring pressure before putting springs on heads they had 745 psi and were rated for 747psi. I have checked and rechecked lash settings I ran a comp. check with 180 psi on all cylinders. timing is lock at 36* this cam is a 4/7 swap solid roller it is the first 4/7 swap cam I have ran I think it sounds different from the left to right bank. they were new sparkplugs and I put another new set in. I'm using the same distributor msd 6al 8000rpm chip and coil as was used with the old motor. at idle ech header pipe is about the same temp so all cylenders are firing at idle. Off idle or under load don't know.
sarry for the long post