Tunnel ram---jetting???

[Jim W]

Hello
I have a 396 BBC with a Weiand tunnel ram with 2 450 Holley's on top, Hyd. cam, pump gas.
At WOT I can only get about 4,500 RPM. The plugs come out pure white but no blueing of the ground strap or electrode just a snow white plug insulator.
Sooooo do I richen only the secondary jets or primary and secondaries?
I am just thinking that by richening the secondaries with the tunnel ram design I will only be richening the intake runners by the secondaries and not the cylinders by the primaries?
Any ideas about how many jet sizes I should jump up to start with?
Thanks, Jim

[steelcomp]

two.

[Fiat48]

Get the carbs back to stock form and go from there. I have a feeling they are not.

[sanger rat]

450's have 58.5 jets in the front. Plates in the rear.

[Jim W]

I took the carbs off. List #4224S
They have 68 jets in the front and plates in the rear.
Should I just jump the front jets up in size or go to a kit giving me rear jets also?
I have forgotten how the rear plates work? I remember they flow fuel but not much else. Its been a while since I have been back into carbs.
Thanks, Jim

[sanger rat]

4224 list as a 660 cfm. Stock front jets 76. Rear plates 134-12

[Jim W]

Thanks Sanger.
I am not surprised the carbs are not what I was told.
Still wondering if I should get the rear metering block kit? And how the rear plates work?
Thanks, Jim

[sanger rat]

I would put them back to stock and go from there.

[steelcomp]

I would put them on ebay. Those carbs are good for only one thing. WOT.