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Here’s what you can expect when doing a 350 when the new heads are released. The rest is as follows;
Edelbrock VRS 750 carb
RPM Intake port match by Peyton Hunt
Comp 1632-16 rockers
Comp 85701-16 roller lifters
Custom Comp Hyd Roller, 233/238@.050, 108 lsa
FAST XDI Ready to Run Dist
New Mahle SBO 4.125 bore piston kit
Molnar 6.00” H beam rods
N crank
1 3/4 dyno headers and 2.500” exhaust
93 pump gas
1.00” open spacer
Torquey little bastard!
Last edited by cutlassefi; Dec 9, 2025 at 02:38 PM.
I didnt do anything to the speedmaster heads except have them milled down to 64 CC on my 358 build and they made a tad more tq then these new heads, you did make a little more HP then I did, but then again I didnt have my progression HEI on the dyno either. I dont see the point of spending way more for no gain, at least the new heads have a scallop and you dont need to run an elec fuel pump so I guess you make up some saving on that end.
Nice build. Dave, you were down about 30 HP and up over 10 ft-lbs of torque? I wonder if the slight torque loss is port size, larger port intake and as cast head port or just the at 10 degree larger cam?
Nice build. Dave, you were down about 30 HP and up over 10 ft-lbs of torque? I wonder if the slight torque loss is port size, larger port intake and as cast head port or just the at 10 degree larger cam?
Mark didnt mill the heads either, so there might not have been around the same compression. Either way its a nice build with out of the box heads. I thought dale said something about port match, to much for a 350?
Mark didnt mill the heads either, so there might not have been around the same compression. Either way its a nice build with out of the box heads. I thought dale said something about port match, to much for a 350?
If it is zero deck and a .040" head gaskets, it should be right around 10.25 to 1. The bigger bore and a 7.2cc smaller dish bumps it around to 1 higher vs his last mule. Either way over 400 ft-lbs from the start of pull with well over 450 HP is no slouch. Nick's is struggling to get his dyno read at 2500 rpm for some straight 6 builds.
Good job Mark!
