KVB: If you're not aware of it, you should get a copy of Leo Santucci's book, "Chevrolet Inline Six Cylinder Power Manual." He outlines several key points and issues when rebuilding a "Late" Chevy L6 [230, 250, 292].
TJ: What don't you like about the 390 Holley? The price? At $476.95 for the 4160 version, 0-8007; and $609.95 for the 4150 0-80507 -- I'd have to go along with you.
I ran the R-8007 on my 292 from 1979 to 2002, but I paid $82.07 for it new, then. After a rebuild on a different 292, that carb ran OK thru the 500 mile break-in, then went erratic. We figured the throttle plane might've warped over 25 years, so I just got a new Edelbrock 500 CFM 1404. I prefer the AFB design, personally, as I find it a lot easier to work on than Holleys. Economics was a major considertion. The Edelbrocks cost much less.
[I found myself placing my old 8007 on my Offy intake to check control attachments, in case my 1404 was sidelined for missing parts. When rebuilding the Performer this week, in rustic conditions, I managed to lose a high idle cam/choke linkage in the dirt and didn't want to run an incomplete assembly. But my local High Performance vendor, Don's Hot Rods, comped me a replacement linkage. So I'll be OK.]
I remember putting a 50cc accelarator pump kit on that Holley, and it would stomp!
Great T. Lowe video, that guy's amazing. He's a big contributor to the forum at Inliners International's website:
www.inliners.org
Anyone thinking of building a Chevy L6 would be well advised to check that site out.