BBC symmetrical heads

[SupStk]

I've been considering the purchase of a pair of symmetrical bowtie heads to be used for fast 16 and Super Pro ET racing. There is an extra head in the package that has been used for expermenting. The price is "right".
I am considering these to go on a 565 CI BBC (4.600x4.250).

Where the development is at now:
Sized for 4.500 bore
Intake Valve 2.450, 470 cfm@.700
Exhaust valve 1.850, 340 cfm@.700
The seats and guides are installed, porting is roughed out and chambers are semi finished.

My questions are:
Are there any issues with these heads, other than special pistons, shaft rockers, titianium valves?
Do those numbers match what good heads do?
What HP and TQ can I realistically expect at what RPM's?
What does a person do for an intake?

Thanks

[SchmidtMotorWorks]

I think for some manifolds the distributor is an issue too.

[ZEROMAN91]

Some of the guys around here had lifter problems, I'm not sure if they got' em worked out yet. I belive it had something to do with the valve angle and lifter side loading.

[SupStk]

Thanks for the input.

SchmidtMotorWorks; The distributor is a belt drive Jesel, so no issues there that I'm aware of.

Zeroman91; On the lifter problem, how much offset is being used on the intake rockers? The guys you know of, are they using larger diameter lifters and offset seats?

Thanks again for your time.

[ZEROMAN91]

I'm not sure of the lifter offsets off the top of my head but I'll call and ask . When I hear back I'll let you know.

[SupStk]

In other applications I've used .750" offset on intake rockers with centered lifters haven't noticed adnormal lifter bore wear. However I'm not sure how much offset these heads will require.

[ZEROMAN91]

SUPSTK : I checked with one of the builders of those sym port motors, the problems with the lifters were brought on by insufficent valve spring pressure for a large size stainless valve. The people in question switched to titanium valves and Crower lifters and springs and the problem went away.!

[SupStk]

Zeroman,
Thanks for taking the time to check this for me.

[shawn]

hi,
you might try emailing Darin a R&M about those heads. I'm pretty sure he's seen a set or two during his time. As far as an intake goes, it all depends on where they "put" the intake ports and whether or not they rolled them a bunch and corrected the manifold side to any standard. Most likely you'll be stuck having to do a sheet metal or heavily modify a cast one to fit. I haven't seen the new edelbrock piece, but the impression that i get is that they left enough metal in it to fit about anything. The R&M piece i believe is the same way,but again, Darin could set you straight on that.
shawn

[SupStk]

I bought those heads. Turned out the port work wasn't roughed in but the seats and guides were installed after the combustion chambers were welded on the exhaust side. Guess i have a clean canvas to start with.

I've spent more for less before... they looked too cool to pass up.

[John Haskell]

One thing I found on working w/those back then was, you should re-cut the seats w/a torque plate. The heads do not have much aluminum for a good solid base. They tend to move around some. (Guides & seats) I also noted the cams have to be specifically ground for the casting. Valves are not really located properly for overlap issues as I remember & the boys who figured them moved the valves. -------- All in all, a high maintenence head, I thought.