What should I look for when picking a 1in. carb spacer? Is there anything special to this? Is it depending on the type of intake I have? Thanks. I have one on the intake now but it was used from the old intake I had that was on the car when I bough it. I replaced it with a performer intake.

 

I chose the 1" Edelbrock Phenolic open spacer initially on my stock 350 with Performer intake/600CFM Edelbrock carb.
Had it on for a couple months then it cracked.
I read some a few articles about these spacers and found that the 4 hole spacer makes more lower end torque, while the open is more for top end.
I then installed the 1" 4 hole, noticed a little difference. Money well spent I feel.
So my vote would be a 1" 4 hole spacer for mainly stock.
I'd be interested to see what other guys are running and what works on their engines.
Hope this helps
Eric

 

Why have a spacer ? And will you have clearance w the performer?

 

Well I didn't know if the spacer had any advantages or disadvantages. There was one on the car when I bought it. Had the original stock intake for a 350 and I switched to a performer intake and still used the spacer with four holes but after doing some reading I found out that for a performer intake that you have to use spacers for an edelbrock carb. But I'm thinking of switching to the quadrajet made by Holley and it says no spacer is required. So I'm wondering if I will tell a difference once I swap carbs and don't use a spacer

 

Yeah that's what's on there now, a 1in 4 hole. I noticed without the spacer that my edelbrock carb has linkages that won't clear the EGR plate. So I'm thinking of switching to the quadrajet carb. It says it will bolt right on with no spacer required. Just wondering if I will tell a difference without the spacer once I switch and if it will be good or bad

 

Why not use a spacer?... especially if you have the clearance? insulating properties ?

 

I bent my linkage back a little to clear on my first carb (600edelbrock reman) without a spacer, When I replaced the carb with a new 600cfm thats when I added the spacer. I think it added a little more torque on my 76 smog 350. Not to mention it keeps the carb much cooler.

 

The spacer you speak of that was on your stock manifold is I'll assume an adapter to go from spread bore to square bore carb. Since the Performer is made to accept either, no adapter or spacer is required.

 

I did a test on my 455 with a Torker with a 1" open spacer and a 4 hole spacer with a Q-jet and a vac sec Holley 750. For some reason, my engine respond better with the open spacer with the Holley and feel more torque.

 

There is no hard and fast rule on spacers (or no spacers). This is a fine-tuning aid and how well it works (or if it even works) depends completely on the specific car and engine combo and how it is used. Just because a spacer added performance on one person's car means nothing for another car. Back-to-back testing at the track under controlled conditions is the only way to know for sure.

 

The spacers are too expensive, I would buy a 1" four hole and open spacer and give them a try. Or you could make a couple out of wood and see which one you like better if any.
I found the 4 hole to be better on my stock 350 than the open spacer. I like more low end torque myself so the 4 hole worked out the best for me with a performer intake,600CFM carb, headers,duals,and 3:42 gears, TH350 shift kit. Low compression 350 with not much of HP( 200 if I'm lucky)
Hope this helps
Eric

 

I used a 4 hole on my stock Q-Jet and stock intake on my stock 350 in my 78. I didn't feel any kind of performance gain.

But it's insulation properties cured a hot-start problem I was having especially in the summertime when running the AC, which is why I installed it in the first place.

I run a different set-up on my non-Olds. A Performer RPM manifold and a Edelbrock carb sandwich a 1" open spacer. I ran it for the same problem... curing a hot start problem.