I have a couple questions regarding spacers.
1- If a 1" spacer is good, is a 2" spacer better?
2- I have a 1" and a 2". How should I determine which one, if any I should use?

454, holly 750, mild cam, performer RPM dual plane intake, stainless marine exhaust

Try them all, but I have found they hurt performance.

I have 2" super sucker spacers on my engines. They added 18 HP on the dyno.

Hey Linster, what do you know of the Super Sucker 4-hole, 1" and 2" spacers on something like a Dart open plenum intake? Have you found that they usually hurt perfomance as well?

I would try both of them and see witch one works out best.
I had good experience with 1" four hole spacer in a´454 duplicated 420 HP engine with Holley 800. GM dual plane hi perf ALU intake. The power increase was little but throttle response was improved.
What works on one engine does not always work on another.
4 Hole spacer should work all way up, open spacer helps top end horsepower, but cost you a little low end torque.

I think to remember that Edelbrock does not recommend the use of spacers in combination with there power package, but I could be wrong

OldSchool, Thanks, I was wondering about the Super Sucker spacers. That's a nice increase for a carb spacer! You posted the above while I was still typing my questions to Linster.

Your welcome, my intakes are single planes and the carbs are 1050 Dominators. I've only run the boat three times with these engines and, I think due to the spring cold water temps, there is an azzload of condensation that collects on top of the intake. I'm assuming that it will decrease once the water temps warm up.

You could be right, but I have always found condensation beaded up on the runners/plenum area of my intake manifolds-----even in the middle of summer with warm air/water temps. I usually lift the engine hatch after I come off plane just to check things out and that is usually what I see. The harder I run it the more condensation I see beaded up on the intakes. As it stands right now I use a 1" phenolic 4-hole carb spacer, but I have had some interest in the 4-hole, 2" Super Sucker spacers.

Linny, I am still interested in any findings you may have as I DO value your input. Thanks

OldSchool, I forgot to ask, what did you find when you installed the Super Suckers as far as jetting goes? When you installed them with your engine sitting on the dyno...did you find that they leaned the engine out and required larger jets in the carbs or opposite, same or what? Thanks again

I didn't do any of the engine work, it was done by JC Perf. Oil changes, tuneups and bolt-on stuff are the extent of my mechanical abilities!!