'02 express 5.7 exhaust manifold problem; warped?
Re engining a work van. 5.7 vortec 2002. reman from jasper. old exhaust manifolds will not quite fit on new engine. Manifolds have gotten shorter somehow, warped? Can bolt one end on, but after starting bolts at one end holes for bolts at the other end do not line up with head; off by about 1/8". If I start at the middle I can get either end to start (barely), but once I get a bolt in one end the other end is no go.
Is this common? do these manifolds shorten up over time with heat cycles/warping? What is the fix?
Considering drilling out bolt holes in manifold to allow a little more clearance, but there isnt a ton of extra material there. create a jig to spread them, bolt them on, then remove jig? heat them up with torch to grow them a little, then bolt in place? all ideas I have feel like asking for cracked manifolds down the road. Should I buy new manifolds?