dual quad small blocks?

djwhog said:

Man I see what I started! irat:

I ended up with a polished air gap and an 800 avs and well jet and rod it as needed. I kind of would of liked two 500s sitting on a dual quad, providing the plenum, runners etc were tuned good as well. Am am sure I should still make decent power on the 416. I used to have an old offy 273 dual quad, sold it, and it would not have been the hot setup on a 340 set of heads anyway.

Yep I wanted the cool factor, but performance too. And while I love the look of the 6 pack ouch pricey! And one 4 is easier to tune too.

Click to expand...

I have an addiction to intakes and other things I can polish. I even got intakes and parts for engines I don't own.

inline dual quads:
offy version is a single plane with VERY SHORT RUNNERS. I think this is why they have never really caught on, especially on a street car. The Edelbrock D-64 and D-66 are dual plane dual quad manifolds and they seem to work better especially on a street car. I'm putting together a D-66 with progressive 500 AVS2s.

Below is my STR-12 with Eddy 500 AFBs. I have been running it on the street for over 15 years (maybe 20,000 miles). About 15mpg. a blast to drive!!! I have learned a lot about these over time and am willing to share info for anyone who actually has one that they want to use. First lesson is installing the modifications in the Direct Connection Engine book, which deals with fuel puddling in the plenum leading to backfires.


Never use the single 4 or 6 pack STRs (only available for big blocks) A quick look at the inside of the of the manifold shows why - The cross ram carbs sit over the end of the long runners where the others sit in the middle with the ports facing away from the carbs.


AMC proponents got enough prepaid advanced sales and Edelbrock made a run of the STR manifolds for them several years ago. I haven't seen an STR 12 for $1200 in 10 years. Here's what I found at Mopar Nats last year.

The D-64 & 66 are small port manifolds. To seal well, the top of the ports at the head should be built up and the port mouth reshaped.
I'd certainly buy a new big port dual quad Edelbrock if they made one.