carb spacer?

[shaun89]

i have a 770 truck avenger and decided to buy a 1" spacer, my question is should i have bought the open spacer or will i be ok with the 4 hole spacer, i don't want to block any holes i shouldn't have to let the carb function properly,any input?

 

[rcamacho]

Four hole spacer should be fine, it will improve low end response on that bic carb a bit. Prepare to re-tune the acc pump and mains at minimum though. What size engine and manifold are you running?

 

[454k30]

you should be fine with the 4 hole one. The open spacers are designed for single plane manifolds and the 4 hole and divided spacers are normally used on dual plane designs. They do help with low end a very little bit and it helps to keep the carb a little cooler. As was stated earlier expect to retune it slightly.

 

[shaun89]

i actually got through to holley tech help cause it suppose to rain tomorrow and had to know right away and get it done, im running a 350 with 415hp, its a crate engine from Hi tech engine components, ported vortec heads, a pretty lumpy cam (.525 lift and 218*/228*) and other goodies, im not sure about the manifold size? but what kind of tuning to the accel. pump cam and main jets would i have to do? i already jetted it down from #74 mains to #71 jets, but i havent messed with the accel. pump cam yet, im thinking it would need a more aggressive pump cam? i never knew i would need to tune it from putting a spacer in, thanks guys