Has anyone upgraded there intake on there 7.4(330) engine? I am thinking of doing it, not sure what gains to expect, some have said 15hp. 15hp should be 1 mph.

I run Edelbrock Rpm intakes on my 330's on steroids...I made many changes at the same time so cant help you with the gains....dont think you will see the differance with out some other up grades....start with exhaust and work your way down...my .02

I had a 7.4 330 in a '95 22 Scarab. I changed the intake to an Edelbrock Performer 2-0, changed to Eddie Marine exhaust, and went with a Holley 650 carb. I saw absolutly no gain in top speed. The engine did seem to have more midrange punch but that was probably because the Holley carb was a spread bore. Next I pulled the engine and changed the cam to an Ultradyne grind and bought a slightly used set of rectangular port heads. This made a huge difference. I gained 8-10 mph top speed but spun 3 main bearings after one season.

Why be dismayed? Change the heads on this motor to make more power. If you are on a tight budget and dont want to pull the engine you can replace the heads and intake only and probably see 5 mph gain. Find a set of slightly used rectangular port heads. Bring them to a head shop and have a valve job done and shave the heads about .030. The extra compression and better breathing heads will make more power. Buying used parts and a new gasket set you could probably do it for around 500-700 bucks. Some people have good luck with the 7.4 cast bottom end but I didnt.

Ron

If you even bother with the intake get a used set of heads
I got large oval heads and had them ported and polished and port matched to the new intakes.
(have not fired it up yet so I cant tell you what gains I have seen)
but when you take off the pancake cast iron manifold and look at the intake ports. your going to cry.
Hell you can barely stick your thumb in there,
large oval, you can stick your head in there!!!

Intake, few rpm's not much
new intake with new heads
priceless

Jason