You can shine a turd all you want, but you just end up with a shiny turd.
Don't forget the cost of coolant, oil, gaskets, time, tools, etc. I wouldn't pull off E7s unless I was going aluminum or got a great deal on some worked GT40s.
When you look into the port and see that big ole bump sticking up and all ...
Well ... strange as it seems ... I've seen it said they don't inhibit the flow
all that much.
Gasket matching is way over rated :Word:
That is N O T porting
Work around the guides and bowl work is where some of the best gains
are to he had.
I'd bet for every 10 pairs of ported E7's you find around ........
At least 50% of em are not done correctly and the gain is gonna not be
worth the trouble to swap em out like Adam said.
Thumper knows what is what on those E7's
I say look at the cost of a pair of E7's that were ported correctly and
don't forget to include springs. Also if they have been milled ... you
may need pr's.
Anyway just compare the price between them and some iron
40's/40p's or any of the Aluminum choices.
O yeah ... most of the used heads you find are gonna need a
refresh and possibly new springs.
My E7's don't have gasket matching, but they do have 1.94 intake/1.60 exhaust valves; in addition to new springs. Not 40's, P's or aluminum; but one of my heads is cracked and needed new ones. Not too bad of a find for being in a pinch.