What's the correct base gasket to use for a Edelbrock 1405 on a stock 383 intake manifold? I'm guessing a squarebore gasket (since both the intake and the 1405 are squarebores), but would a 'open center' gasket work, too?

Thanks again!
David

A 4 holer would connect the 4 holes in the carb bores to the 4 holes in the intake w no disruption to the transition whereas the open would work but would disrupt the mixture flow somewhat maybe by interupting the inertia of the moving column(s) I would assume and that would cost you some power. Grab as thick a 4 hole square bore gasket as your hood (clearance) will allow & your (correctly) all set.

Ah ok- so both would work, but the correct one is the square bore cutouts. I'm getting ready to rejet the carb and the reason I asked was because when I pulled the carb to change the jets I found the 'open' type of gasket, and I'd like to make sure I've got the right gasket before doing something as rejetting as I'm sure that'll affect my results...

Thanks again!
David

eddy has a 3/8 thick gasket that has a divider strip down the middle and one thats open plenum type

so the prim and 2ndary side are together in an ovel shape hole

it should be used on a divided intake

a 4-hole gasket should be used on the 4-hole intake

I used the 3/8 gasket on my 600 and duel plane intake that just had a divider down the middle

they also have a thin metal plate for putting the square bore on a spredbore intake that works well also

Does anyone have any part numbers for the square bore gaskets that I could give to the counter guy? I went to NAPA today to get a square bore gasket and all the computer gave the guy was for either the 'open' type or for the 'divided' open type (primary isolated from the secondary, and it looked like it was for a spreadbore). Or would I be better off going to someone else for this?

Thanks again!
David

Keep on them until they find the correct one as it's in their system somewhere. EDIT have them check Felpro's offerings

Your choice,all I need is an address.Incidently,any difference in performance would not be seen unless on a Dyno.Under normal driving conditions,you couldn't tell one from the other.

have them look in a elderbrock catalog its in there

I also use the 4-hole stacked alum plate heat disapator

2 sets made a 1" spacer that had 4 holes and was square bore

IIRC,6-7 plates with 6-7 4 hole gaskets stacked up

even had that set up on the spredbore holley on my 440

the eddie divided one looks like the 2 upper right left ones, but with a thin divider down the middle to make ovel holes with prim and 2ndary hole together

I think the 4-hole like I use gives a better vac signal to the primary venturies

but..what ever works with no leaks is good

@62maxwgn - thanks for the offer, but that's ok- I'd like to find 2-3 of them to have around and I'm sure I'll find them locally, it's just a matter of giving the counter guy a part number to work off of....

@scratchnfotraction - so when it boils down to it, it doesn't really matter (that much) which configuration I go with then? I'm not that concerned with that small a performance difference and more concerned with how much each type gasket would affect my rejetting the carb (and it sounds like the answer to that is 'no difference'). If so, then I'll settle for the 'open' style gasket. As you say, the important thing is that it seals and the store DID have that type in stock at least....

eddie recomends there 3/8 fiber gasket with the correct open or divided plenum center depending on the intake

I needed the 1" space to clear the eddie duel fuel line on my eddie carb

I run the LD4B eddie intake which is divided,but I gained a little throttle respones with it being a 4-hole x 1"

I run the holley street domonator for a sb with the same 1" stacked 4-hole space also but with an open gasket on the very bottom to seal the plate to the intake open plenum

I have been trying to find a couple more sets to make up some 1" and 2" stacks for the square and spredbore carbs I have,for more tuning

what store near you? how much they went fer?

you can PM me so it not a want ad

I'm running a stock 1969 intake manifold on the 383, and it's a square bore manifold. I guess that's part of my confusion right there as I would've thought that the Eddie square bore matching up with the intake manifold like that would require the square bore gasket.

The store I went to is a NAPA. But I've also got a Autozone and O'Reilly's nearby. The 'open' gaskets are going for around $2.50-$2.75 each for paper, but I'd like to get a composite if I can.

I'll hit up O'Reilly's tomorrow and see if they might have the squarebore- I got some FelPro part numbers I can give them to try looking up.