Box_Man

What are the differences between the stockport holley manifold and the brigeport holley manifold? The stock pictures are the same, and the descriptions are less than helpful.

trochoid

iTrader: (6)

The BP has the top of the runners under the carb machined down 1/2-3/4" to make a small plenum. I don't know if that's to make better use of the overlap or if the BP carbs butterflys need more clearence.

Box_Man

Hmmm... I was thinking about that. If that's the case, I'll just buy the stockport one, and port out a carb spacer to get the same effect, as I have to run one with an edelbrock anyway.

Jeff20B

iTrader: (13)

Trochoid, I didn't know the runners were machined down. Perhaps thd one you have was modified by a previous owner?

As far as I know, the only differences between the manifolds was a brake booster fitting on the stockport and streetport manifolds and no brake booster nipple on the BP manifolds with the runners slightly hogged to clear the larger butterflies of the double pumper carbs.

The only time I've ever heard of any type of plenum mods on these manifolds was if the end user decided to cut a channel or two to connect two or more runners together if using an out of the box carb so none of those expensive RB mods were required.

trochoid

iTrader: (6)

I had 2 Holley setups, both bought off eBay used. The milled plenum in the BP one looked factory and it was my understanding from RB that the larger carb butterflys need it for clearence.

This intake had more than channels cut in it. All the material seperating the 4 runners was cut down level at least 1/2". It did the same thing as adding a spacer with a large square opening.