6257DP Primary vs Secondary

Question

6.54K viewsMarch 13, 2017

0

Mattroy10 March 13, 2017 1 Comment

Greetings,

I have a 6257 DP installed on my CJ7 and about to strap on a Holley 390. I can’t find any info on which plane is the primary vs secondary. Summit Racing says the smaller ports (bottom, further from the motor) are primary. However, I’m seeing images online of 4 barrels mounted backwards with the primaries on the upper plane. Please help!

Thanks,

Matt

Mattroy10 commented March 17, 2017

Info on this would be greatly appreciated. Thanks!

1 Answer

score 0 · Answer 1 · 2017-03-29T20:08:28+00:00

Summit is correct. The primary plane is the smaller port. It is possible to mount the Carburetor backwards, but the performance of the manifold will be hindered.