[ChevLoRay]

In my opinion, the 4bbl would be preferable, over the 2bbl, with the same cfm rating. The 4bbl would use the primaries until you kicked it into WOT mode. This would give you better mileage and have more fuel available for power, when you needed/wanted it.

I wonder about the 7K rpm desire. I had a '67 Firebird Sprint, with a 230CID OHC 6-cyl. It came from Pontiac with 10.5:1 CR, dual exhaust manifolds feeding a V-8 single exhaust system, a Quadrajet on a 4bbl intake and a hotter cam than the stock OHC-6's. I think it was supposed to be good to 6500 rpms. In '68, Pontiac went with the 250 block, and added the goodies. The horsepower rating didn't change, from the 215HP that was advertised. I don't know what the SAE HP rating would have been, since it wasn't until '71-72 that SAE became the standard rating system. I guess that having 7 main bearings is the key to having higher rpm capability. Older, i.e, earlier, designs used 4 mains and that led to some crankshaft "whip" as rpm's increased. One thing to watch is the harmonic damper. On some 292's used for drag racing, one racer had a problem with his engine when he seemed unable to keep the harmonic balance on the crankshaft....or so he said that was the problem. There could have been other factors that he didn't disclose. But, at least for him, it was a problem.

Sounds like a plan, though. A good split manifold, or headers from Clifford, with their 4bbl intake and you should have a unique-sounding engine. I always liked the sound of a straight six, with duals, especially when running glass-packs. They really sound sweet when you "wind 'em up and let 'em rack off".....having that occur in some old downtown settings where the echo really accentuates your presence to the local gendarmes.....well, now you know what NOT to do. My old TR-3, also caused the plate glass windows to vibrate. Ah, the joys of youth.

Go for it. You only live once, and whatever you have.....well, you can't take it with you.