Some History for anybody interested. No wars wanted, go check it out for yourself.
The "EZ" INDY head was a result of INDY's desire to compete with the new,(at that time), introduction of the BULLDOG head, with the much "BALLY-HOO'd " HYPE !
Seems that it was one of INDY's pattern makers, that "jumped ship" as it were, and went elsewhere, and began production of the BULLDOG head for himself/new employers/partners ? Hence some similarities of the BULLDOG to the INDY SR.
INDY, not one to lose claim to the "best street head" moniker, that argueably, their INDY "SR" head held at that time, redid the "SR" head, albeit, with the revised, and lower, exhaust port configuration for direct competition with the BULLDOG's "stock exhaust port location" sales pitch.
( A PROBLEM FOR THE INDY"SR'S" at the time, WAS THE RAISED EXH. PORT WINDOW AND HEADER/APPLICATION CLEARANCE ON RB BLOCKS) The "SR", and all INDY heads, were designed to place the exhaust port location, when used on a "B" block, in the same position, as if an 'RB" had been used, for header fit. Problem was, when used on an "RB", it was "up & out" a further 3/4" further still ! Can we say "header grief" !! Same Common exh. port location to all INDY heads, 440-1, 572, etc.
Interesting note here, was that up until that time, the "SR" head was considered a "WOLF IN SHEEPS CLOTHING", and argueably, the BEST head out there, for those wishing to upgrade using stock intake manifold, rocker gear, etc., etc.
Many magazines, and builders, including myself, could attest to, and document, up to 340 cfm on "critical" benchs from INDY SR heads, in a fully ported version, utilizing max-wedge port window.
"HOLY BIG AIR BATMAN ! " for a bolt on head, that accepted a customers stock parts ! Albeit remember the aforementioned "header/application" pains of the SR.
INDY re-did the "SR" slightly, with a "stock location" exhaust port, and presto ! INDY "EZ" head WAS BORN !
IMHO, no wars wanted, I personally have to give "the nod" in a price/power potential comparison, to the INDY EZ head, and INDY quality control in production, for fit, finish, and proven ease of useable power, especially when strokers up to 500 inch are contemplated. If header clearance is not a problem, the SR version is still offered also, and delivers more at the higher rpm's/nitrous, with the raised exhaust.
If price is a factor, EDDY's are a great head also, as are many others, but the rest are "comparably" priced closer to the INDY EZ & SR. Seems "we get what we pay for", is in effect.
I could go on forever, but I'm too long winded already, "bottom line" is that there's lots of "great heads" out there these days for one to choose from. Makes re-working the old iron stuff pretty much redundant price-wise when considering final product we want. We're WAY BETTER off than 10-15 yrs ago !
Good luck and hope this helps, with whatever head you choose.
