[Lightingrod]

I have a couple of Holleys and a Demon sitting on the shelf but I went with a new Edelbrock Thunder Series AVS 800 CFM on my SBC 388. IT DID REQUIRE TUNING!

That being said I agree with pretty much what everone else has been saying! The part about them not liking really big cams is a fact! As to secondaries, yes they are vacuum and don't have an acc pump. However unlike Holleys they use an air valve and not a diaphram. The air valve takes about 10 seconds to adjust and is much faster to react than a diaphram.

The 388 was an all new (to me) engine except for the MSD HEI. The carb was bolted on right out of the box and the timing was set the same as the 383 I was replacing! It idled and ran good with good throttle response but went DEAD about 4,000 rpm. I got the timing sorted out, 18*/18* and all in around 3,000 rpm. The timing changes made a big difference but it was still laze above 4,000 rpm. The plugs told me it was rich. After reading Edelbrocks tuning guide I came close to yanking it and putting on a 750/800 Holley. After a little more reading I understood it's theory of operation and decided to give it a chance! I did a rod change (only requires removing 2 screws) that would keep the light throttle the same but lean out the power mode. It was the right direction. I selected rods and jets to lean out the power mode by 8% while keeping the light throttle about the same. Solved the WOT rich condition but now had a slight hesitation when nailing it from a dead stop. I slowed the secondaries just a touch and it seems pretty darn good all around. You can also change the rod springs to change when the transition from light throttle to power mode occurs, like the HG rating of a power valve on a Holley! My cam is only 236*/236* @ .050", I think Edelbrock recommends 245* or less duration.

I'm pretty happy with it but that don't mean I will not stick one of the Holleys on just to see!