Manifold Installation Question

[Fasted]

On a 1973 340 with 360 heads. The manifold i removed had the mounting holes oblonged so it could be bolted on. The new Edelbrock RPM holes do not line up. They are about 3/16" off(up). Do i need to mill the manifold at where the head mates? Also, the intake ports on the heads are about 2.15 tall, but the ports on the intake are about 1.90 tall. How do i make sure they match up? Is this "port matching" and, if so, how is that done.

[pishta]

Lay the intake on without any gaskets or cork rail gaskets, do the holes still not line up? You may have shaved heads but more often than not, you have too thick of cork rail gaskets, pitch them and put a bead of RTV there toi make a gasket. Port matching is the process of getting the ports to line up, hogging out the intake is the easiest. I do a dry install and try to read the intake gaskets or blow some talc in there with the rocker arms not installed so all the valvs are closed and use the outlines to guage how much needs to be removed. The roofs are more important than the floors, but its great to get them all lines up.

[OHD]

When swapping parts you have to make them fit.


1: determine how much the heads and decks have been cut
2: determine if the heads need adjustment (amount other components have been cut)to fit with the gaskets you are using (contact the head manufacturer and manifold manufacturer to get the straight poop.)
3: make any necessary cuts to manifold and get the clamping system (bolts) to work freely
4: if the holes need readjustment it is best done on a fixture on a Bridgeport sleeving/plugging the old holes to get a straight clean hole.
5: test fit and repeat until everything bolts up.
6: when all bolts line up and everything goes together smoothly, bolt bare heads on the intake manifold and turn over. spray bluing marker in the intake ports towards the intake manifold on both sides.
7 take apart and you have the blue where the intake manifold "blued" where it needs opening up. Make sure you taper the cuts, way up into the manifold for smoth air flow. Finish in 80 grit.

Not simple....but performance related.... I have done it about a zillion times...and it works every time. If you have any questions call 301-277-4433 and I can walk you or your machine shop through the proceedures. Glad to help anyone get a job done correctly....

[namvet67a1f]

So OHD .....

Do you do any cyl head flow work ?

[Fasted]

Thanks everybody. I will update what i come up with.