Wow I would of thought the top end would of been alittle more noticable with the .96! I'm plan on doing a similar test with my 6L + GT 76 and a .70 & .96 a/r housings. If this is a reflection of what's gonna happen I may just leave the .70 on there. Like the 1990's super detective said "100 extra HP at 65 mph sounds strong to me" too!

 

jim i wonder what you would get if you swaped out the heads.
larger ports, larger valves, it would flow allot more.
damn i wish i was up there helping you work on this.

 

I was talking with someone that's a lot smarter than me today...(happens alot ) and they suggested the same thing. Could be the heads are maxed out flow wise and was the limiting factor. I had originally thought that the different A/R would make a bigger difference. After seeing this thread I had dropped the idea of trying this on my set-up but now think I will try it anyways, just to compare and see if my numbers reflect the same findings as Parish's.