Quote:
Originally Posted by harpo231
On the L31 Vortec heads, the exhaust ports are not centered on the bolt holes. This results in a mismatch of the exhaust ports of the heads with any manifold or header other than the L31 manifolds. Really not sure why GM did this.
|
Harpo is correct the exhaust studs are set lower and not centered as in the older gen1 sbc head , just hang a set of sbc gaskets on and you will see this so ,there will be a small amount of interfearance at the top of the ports , will the rams horns fit yes they will and any gen 1 sbc exhaust manifold or header will fit, some guys say you want to use round hole gaskets and headers in stead of the oval/d port gasket and headers , I did some grinding (porting) and a little gasket moding to my headers so there was no interfearance issues on my vortec heads, also the rams horn might be close to your spark plug boots and cause issues . If you are staying with manifolds if I remember rite the best ones you can use for the vortec heads are out of a vortec year 3500 series truck I think ,I could be wrong but I know that there is a certain stock manifolds that is is highly prized for there flow on vortecs by the circle track racers being thety have to conform to stock manifolds those would be the people you want to ask.