I have a 2006 brodix catalog part # for the 294cc runner race rite
115cc chamber. # BRO-2061013.

4cc less on the chamber will help but it won't raise your proposed comp
up to the upper 10s from the 10.2.

Catalog shows the flow, not nearly as good on the exhaust of the
AFR 305 a little less on the intake side. Heres brodix claims.

INT.
.200=160
.300=226
.400=276
.500=314
.600=337
.650=341
.700=342
EX.
.200=116
.300=145
.400=172
.500=196
.600=217
.650=230
.700=236

Don't trade better airflow for 4cc improvement in comp.
The AFR may have a raised exhaust runner that would be the cause
of longer exhaust head bolts. Don't just dismiss the AFR head untill
you figure out if it has raised exhaust port and if that would cause
a problem with stearing box clearance.

theres two different valve springs shown for the brodix race rite heads
one is a hydraulic roller spring # CC904 1.55 DIA, 140 lb closed,
400 lb open, 1.950 installed height, 600 maximum valve lift.
the other one is a solid roller spring, 1.55 DIA, 240 lb closed,
550 lb open, 1.950 installed height, 700 maximum lift.

Make sure you don't end up with the solid roller springs.

www.airflowresearch.com

Looking at there web site the 305 as cast head is available in a
114 chamber, most likely have to order it, they mention 1 inch
longer exhaust bolts, but did not see where it said the exhaust runner is raised, most likely it would be raised with longer bolts.

The AFR ports are raised like .300 or so I think. But there are lots of Vette's out there with them in place without too much hassle. Biggest issue with them is to make sure to spend time on pushrod clearance and rocker arm setup. They seldom work perfect without some massaging and juggling. But they are great heads otherwise and make good power.

I'm a big Brodix fan...some of the best castings in the business. The Racerites seem to be doing very well out there especially considering the restraints of the stock height ports etc.

The AFR 305's or 315's will run killer on just about anything. Probably make a little more power than those Brodix out of the box.


JIM

I called Brodix and they said that they will put in any spring, just give them the spec's for my cam and they will assemble it.

My compression calcultor (assuming 0 deck and 20cc piston) shows 10.3 with 118 chamber and 10.6 with 115. Brodix said the 115 will not flow quite as well. Am I better off with the flow of the CR? They didn't tell me what I would lose by going 115. There is no additional cost to do it.

Interestingly, Brodix recommended the oval ports over the rectangle ports, even with a 489. The flows are the same for both and they said the ovals would give better mid-range torque. Brodix said they were similar up to 6500. I know you guys think I should be sure to flow well up to my redline (6500). I have been researching the race rites a chevelles.com and there are few guys making over 600hp with the ovals. It seems their HP tapers off at about 6000 RPM or so. The runners on the ovals are 280 vs. 295 on the rectangles. What do you guys think?

catalog says race rite oval 270cc runner.
The reasoning for using modern heads is to take
advantage of there better airflow, airflow of the
AFR 305 as cast is a bunch better on the exhaust
better on the intake, seems like you are dimising the
AFR for some reason.
Brodix has a 305 head thats all CNCD, flows air like the AFR
but there $3200.00.
Put up a thread on the forum see if anyone has any header problems running AFR heads.

One thing to keep in mind about flow vs compression (they are actually on the same team)... The better flowing head will pack more A/F charge into the cylinder to compress in the first place.

Over-simplified Example: Take a head that manages only 90% volumetric efficiency (VE) at a given rpm and factor that with a 10:1 static CR. You end up with 9:1 effective compression (some use the term "dynamic" here) Then consider a head that achieves 100% VE at that same rpm, but that only provides for a 9.5:1 static CR. The latter example yields a factored effective CR of 9.5:1, or 0.5:1 more compression. Think charge density here...

Hope that helps.

Good point.

Jim is right, the exhaust port is raised .375. I have a set of 315's on my 69. I am running Hooker sidemounts on mine and it did cause issues with the headers. I had to cut and reweld 4 tubes. I have heard of others who had no problems. I guess every car is different. They are worth the money and trouble though.

Bill

Excellent advice
Burnouts are for kids, a car that hooks and progressively pulls hard oh yeah!!

if the cam you choose wants compression then do it!!

A can of torco or Octane Supreme per tank is cheap youll be glad you did. Bought a 6 pack of the latter lasted me a yr. 100 bux
Low compression builds always left me with that feeling that "somethings missing". snap crackle pop throttle response the way it hits, sounds upstairs...totally worth it. Do it and have fun