Endeavour, I suspect that it is much like the AFR 265's and other "roval" intake ports - you have to port match an oval intake to take full advantage of the flow. I think GM Performance Parts has a manifold that matches up to the "roval" ports on the Edelbrock heads, but it is a dual plane non-air gap style manifold.

I took a Weiand Stealth and matched it to my AFR's, worked great. That's what I was thinking as well, use an oval port intake and blend it. The port opening is close to that of the AFR/Edelbrock other than it has sharper corners.

Just dropped off at machine shop. He's going to check bores, mag rods, and all that needs to be done to know where we are. Probably won't hear back until next week as he's pretty slammed.

I concluded on staying N/A for now so that's how the build will progress. So it's either going to be the Brodix RR rectangle 294 runner or the BB2 rectangle with the 305 runner and .6 raised exhaust ports. HBR(machine shop) says if 100% sure I will be staying as is go Race Rite, but he likes to look past the current build and recommending the BB2 for posible future potential. Noting is on order yet as we just started but I will have to make a decision at some point.

What are your thoughts on either of THESE TWO HEADS mentioned? I'm choosing rectangle so I can keep my current intakes and/or possible future builds are more compatable with rectangle.

Calling Bob M. now to start the cam talk.

fixx
 

Hell yea!!!!! i got all my ammo in a row now so fire away!!!!!:waffen093::greenchainsaw::throw::argue:

This is from an old email I have.
.300" 202 cfm
.400" 260
.500" 291
.600" 302
.700" 320
.700" 401 w/ pipe


I had to raise the floors on my on my intakes. The port maintains the height of the 345 and the floor is raised. The port is 2.1" tall and 1.75" wide (3.675in² at the flange).

I bought these heads for my 454's with the idea that these will be the last pair of heads I buy. I will transfer them to any build I have in the future. They have proven themselves on my 454's. Whether I spun them to 6500 with my old cams or 5600 with my new cams (Bobs) drink ICDEDPPL lol, They are on Valako's N/A 565 (787HP), a pair of 575sci's a pair of 572 Vortech Supercharged engines and many others out there.


If you plan on building more HP in the future I would buy the better heads now.

Wow, that's some good exhaust flow!

Thought I'd share my experience with the BB2+ heads. About 10 yrs ago I built a 555 w/BB2+ heads and mild hyd roller cam.. They had some minor port work at the time. It made an honest 600+ HP at 5200 rpm, which was the target for this build. Subsequently we added a Whipple supercharger with low boost 5.5 psi. Ran great for several years. I pulled the engine and put it on the dyno. It made 770 hp. I changed pulleys to raise the boost to about 6.5 lbs. I made some more pulls and found the boost really spiked above 5000 RPM, and power fell off. Realizing the heads were the problem I sent them to Jim V for a complete port job. After reassembly with a little more aggressive cam it pulled to 6000 RPM and made over 900 HP. Needless to say I'm pretty impressed with his port work. However these heads totally maxed out, still do not flow that well. I've got the flow sheet somewhere at the shop but the best I can remember the intakes only flowed around 350-360 cfm after porting, much less before. Plenty good for a N/A 454 or even mild supercharger IMO.

Bob Lloyd
Full Throttle Marine

Thanks bobl

short update:

Looks like i'm going to end up with one 460ci and one 468ci. Current aftermarket block has 30 over pistons but needs to be bored 60 over. Those pistons are in good shape and will be reused in the stock block which will be bored 30 over to fit.

The build is finally underway!

Excellent! I just finished my build and it has been a long road....... I have lurked a ton here reading all engine building/theory posts...... Lots of great info out there to get the right engine combo for your boat...... TBF