Thomas,
In my opinion you're trying to do too much and it's not necessary. The head
alone along with some minor tuning will give you more than enough punch as
you call it.
The re-designed standard head was first developed and produced by the folks
at SC Parts in England. The re-design of the head solved most of the
breathing issues inherent with the old design plus the added benefit that
this head isn't prone to cracking like the iron one.
Denis Welch took the basic design and casting and brought it up a level.
Mark Lambert of Tennessee, technical director for the Club did an evaluation
on the SC head on a standard BN2 using stock H-4 carburetors. He found a
number of interesting things to include.
The effective power range of the engine was doubled, from the stock
2,500-3,500 to now 2,200-4,200 RPM.
Mark claimed that the new head gave better breathing than was attempted with
the LeMans modification. It didn't matter that you put bigger carburetors
on the car, you just could not force that much air into an already
restrictive head.
According to Mark, on the re-designed head you could now fit a golf ball
through yjr intake passages where on the old head you could barely fit two
fingers. Also, the larger H-6 carburetors were not needed, and in fact the
H-4's worked great giving a higher velocity of airflow.
Couple this with a hotter cam, balanced parts, and one trick I know that I
personally discussed with Denis Welch was using old Buick Straight Eight
lifters and custom push-rods.
You should get a 100 that will out run a stock LeMans modified car and keep
up with a stock BJ8.
Curt
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