We dynoed my engines with no spacer, open spacer, 4 hole super sucker, and ended up with both the 1" open AND the 1" 4 hole on my Foxwell ported Victor Jr. And a 1190 Prosystems dom

Unless this dominator is a mess it seems it needs more spacer, we will know tomorrow. Im going to bolt the 4150 and its 3" of spacer back on and see if we get our hp back too!

Great info and a ton of work, so thanks for posting the results.

My guess is the efi will have a little less power with a smidge more midrange torque and better manners.

cool, let me see if I can send over next 2 days

Smitty, I think what you are seeing is what a lot of drag race guys found a while back, the 4500, with a spacer/adapter to 4150 shows a strong signal to the carb and works very well, I know a few guys swear by this setup...

I see that more on small blocks.

Big block in general, if they need a DOM, tend to like a Dom manifold too.

My carb guy norm says ssme thing, 4150 modded to flow same as dominator will out perform it in every way BUT i would think 3 or 4 hp here or there, 25+?

Last year , a friend had dynoed with dominators. First one was a modified one from Nickerson. They tuned it on the dyno. It had a good afr from 4000 to 6500, but below that, it was all over the place. Tons of changes to the carb, and they werent happy with it. They put on a box stock ultra gen 3 dominator, made a couple jet changes , they had a rock sollid afr from 3200-6500, and picked up about 18hp if i recall at peak.

I think booster style can play a big role in the fuel atomoization. Straightleg, downleg, annular, etc.

SO - does an EFI gain from having a spacer. I have the HOLLEY 2000 CFM throttle body ( 4500 )

Good question, in a week or two ill know, at least with speedmaster intake, this compression and cam what works, Smitty