PowerAddict

I have a stock 1994 GEN V 454 330. I am adding decent aluminum heads, the 139011 roller cam, lifters, roller rockers, air gap intake, and IMCO Powerflow manifolds.

What do I need to do to the carburetor? Also, should I add a better fuel pump?

Thanks!

NightHawk

The stock Weber carb on those engines often had staggered jet sizes. Different on the left and right sides. You may want to even those up with your new intake. Get a calibration kit from Edelbrock. It will have all the different jets and metering rods and will fit the Weber.

http://store.edelbrock.com/tuningaccessories.aspx

PowerAddict

Is that all I'll need?

NightHawk

Yes the tuning kit comes with lots of different jets for both the primary and secondary. It also has the various step-up springs of different weight and metering rods. Al easily changeable with just a flathead screwdriver. No gaskets or O-Rings involved.

The Weber is basicly a Carter AFB and any on-line tuning guide for the Carter will be helpful and applicable to the Weber or Eldebrock.

PowerAddict

what about th fuel pump? Stock one okay? Should I upgrade?

apollard

From my experience with the weber, it is an OK carb for stock engines. Only issue I had with it was the hard starting after sitting (a common issue). However, when upgrading the engine you will soon find it is the bottle neck. I did a very similar build to yoiurs, and the weber isn't going to feed that engine as much air as it needs. My advice is to ditch it and get a holley. I did and I love mine. My only regret is I didn't go larger than an 850.

And no, I'm not a holley fanatic - they all have thier place, the weber is just not there for a modified engine.

The bonus is that I can go to the boat after sitting for 2-3 weeks, pump the throttles once and it fire on the first revolution.

Kidnova

I agree with apollard. Mainly because I've had Holly's on 3 BB's now, and never a starting or running problem. fwiw, no choke on any of them, I don't like to go boating in the cold LOL.

Also, I'm no mechanic but I believe your stock fuel pump should be ok. I ran the stock Merc pump from my 7.4/330 on a ZZ502/502 for 4-5 seasons and it fed the engine just fine.

apollard

Kidnova reminded me - no choke on my holley either, and I do go boating in colder temps. One throttle pump, set throttle a little above idle, crank, no issues - even on the break in of the engine in 52* weather. Ditch the weber / edelbrock - it works well for cars. Mercs version, not so much.

PowerAddict

well, I was kind of thinking of going to holley, the only thing I was concerned a bout is where to mount the mercathode stuff, and the throttle linkage? do they make new brackets and stuff or do you all just make it?

Kidnova

That I can not answer. But fwiw, about 10 years ago we swapped out a 7.4/330 for a ZZ502 with an Holly 850 (GM Crate Motor). I had a guy helping me, or better said, I helped him. And if I remember correctly we did not need to replace the throttle cable or end. But he did end up fabricating a bracket that would make the 850 work. Again if I recall, it wasn't a big deal. You could take a photo of the set up on your present carb and go look at a Holly to compare, and should be able to determine what you would need to make it work. With all that you have planned, I wouldn't be too concerned about getting a different carb to work on your new set up. It will be a very small bump in the road.