[Aerotech]

My T-bucket's 350 gets a miss at WOT which I suspect may be undersize main jets but have never rejetted so what are the symptoms? Everything else is perfect, performance is extremely strong in all ranges except wide open.

Holley 1850-4 (4160) with 64 mains, stock secondary plate, blue pump cam, white secondary spring. Secondaries kick in very smoothly by 2000 rpm and advance curve is very fast (yellow springs) and also all in by then.

I get excellent launches and tire-chirping shifts, but if I leave my foot on the floor it gets a light sputtering miss around 60-70 mph which clears up if I lift a little. 3.00 rear end means revs are pretty low and it does not miss at all until it hits 3rd.

Are 64 mains just too small? If so, what size should I use? Engine keeps loads of vacuum, so would 85 power valve help or keep the 65?

[sqzbox]

Yeah, you should have 66 primary jets, 6.5 power valve, and 134-9 metering plate inside the secondary bowl. Wonder how the 64's got in there? Keep the 6.5 PV. After you change the primary jet's (seems that's all you need) check the float level and fuel pressure. A miss in 3rd that clears up when you lift off the throttle shows fuel starvation. Good luck!

Here's a holley spec sheet, you magnify ok?

[Aerotech]

Great advice. Thanks.