I've wanted to switch to Trick Flow heads but at $2000+, I wonder if they would deliver enough of a power increase to be worth it.
440 with six pack rods & pistons 10:1, std port cast iron org. 906s w/good perf. valve job
clearance for the valvelift on the guides & decent Comp cam, like .540" gross valve lift-ish
w/an Edelbrock RPM dual plane intake, Holley 850cfm DP (IIRC)
Harlan Sharp Rockers/shafts (IIRC) built by Steve Dulcich (spell)
then switched everything over except the heads over to;
Stealth's Alum (Chineseium) 'std port'
un-ported 200cc (maybe, they claim 212 ?),
bigger 'cheap valves' 2.14"int./1.81"exh. valves
(
not great quality valves either, really need to replace them with a good quality Stainless Steel Valves
at a min. & I can attest to that 1st hand experience's, so add in that expense too)
80cc comb. chamber,
maybe at best 260cfm flow, (they claim 280cfm
) w/std straight plugs
look the most like stock 906s, of the alum heads tested, they are 29#s each
made about 20hp over stock cast iron 906s, across the whole rpm range
base priced at $699.95 ea., you can get better USA sourced parts, by/from 440source.com
but it starts adding up, not a great bargain then...
then;
Edelbrocks RPM 'std port' 210cc
un-ported & true 290cfm+ flow
2.18"int./1.81"ex. quality 11/32" all USA sourced parts/castings, Stainless Steel Valves
(IIRC) use the 84cc comb. chamber, you can get them in 75cc now,
14mm - 3/4" long-reach angle plugs,
need special ARP head bolts/washers $79-ish
across the whole RPM range about 40hp above stock cast iron 906s,
$929.50 ea.
then last;
Trick Flow Alum 240cc 'std port'
are CNC ported
(that's about a $600-$1000 value in most cases, for porting),
& TFs have a
lil' bigger intake valve 2.19"int./1.78"exh angle plug heads too,
(
a tad smaller exhaust valve/than the Edl. RPMs)
a lil' smaller combustion chamber like 75cc
need special ARP head bolts/washers too $79-ish
made about 20 hp more, across the rpm range, than the Edelbrock's
un-ported RPMs,
so about
60-ish hp more than stock with cast iron 906s
it's pretty good investment for HP gains
$1,399 ea.
IIRC each head, one was about $300-$400 more than the previous one, tested
according to Dave Freiberger, at the time filmed/tapped
All the alum. heads, were
closed chamber heads too 75-80-84cc's
all are about 50-ish lbs less, overall combined weight savings depending on the heads,
over a cast iron 906s
Engine Masters did a good show on it, compared them, back to back to back to back
I think it was called the "Wedge head shootout" or comparison (? something like that)
to 1st they ran stock cast iron 906s
then to out of the box Stealth's
then to out of the box Edl. RPMs
then to the CNC ported 240cc Trick Flows...