My 67 Chevelle has a 283. A couple years ago I freshened up the engine, and changed the intake to an aluminum 4 bl and installed a holley 570 street avenger. I also installed a 1" carb spacer. At the time I thought that it was a good idea for helping the fuel stay cooler. But I heard something the other day about using spacers, raise the peak rpm range. If this is true, does this mean that my car is worse off the line using the spacer?

Help?

tas

My understanding is that it depends on the spacer you are using. Either a 4 hole, or one that is fully open. One is suppose to increase torque, the other horsepower. The 4 hole is for torque and single/open is for hp. That's about the extent of my knowledge on them though. Which did you install?

The one I installed is four hole. Not really sure if I should be using one, or what kind.

Thanks,

tas

I experimented with a couple different spacers, and ended up keeping the 4 hole spacer, because it improved idle quality and throttle response. It also made starting easier then the open spacer did. The open spacer did seem to help higher up in the RPM range, but I don't drive there very often and it was too much of a trade off. I didn't have the option of not running the spacer though, even with a low profile vacuum fitting, my double pumper/Performer RPM combo wouldn't work without it. You'll just have to try experimenting with your combo to see what works best, but I'm guessing with a 570, you already have a good signal and could get away without it.

I tried a 1" open spacer on my 454..I had a 102 MPH with and 102.45 w/o...needless to say,it isn't on my car anymore..if you want to keep your carb cool,get a heat shield that goes under it.

Or get a piece of canvas phenolic laminate and whittle one up yourself as I did. Phenominal heat insulation. I used 1/2" phenolic. Open spacers don't do anything until higher RPMS, so if the motor doesnt see 5000+, four hole is the answer.

One router, one 1.75" hole saw, 1'x 2' x 1" Phenolic and you're in biz.

Originally posted by 427L88:
Or get a piece of canvas phenolic laminate and whittle one up yourself as I did. Phenominal heat insulation. I used 1/2" phenolic. Open spacers don't do anything until higher RPMS, so if the motor doesnt see 5000+, four hole is the answer.

One router, one 1.75" hole saw, 1'x 2' x 1" Phenolic and you're in biz. Where can I find a piece of canvas phenolic laminate? Home Depot? Any hardware store?