irocdaddy

hey everyone.

this is my current combo:
zz4 crate with hotcam and 1 to 6 roller rockers. currently tpi.

i am installing a holley avenger carb and need a manifold now. anyone have good advise here? want one that matches well to the hotcam and also plan on ditching the vette heads on zz4 for some 202/1.60's.

how is the holley dominator? i read it is good up above 6500 rpm?

what fits under our hoods?

xpndbl3

iTrader: (5)

those zz4 heads are nice heads, hope you're trading them in on some AFRs, otherwise I wouldn't bother. You could go vic jr, or performer rpm air-gap depending on what your stall and gear/setup is.

irocdaddy

I AM USING THE 96' T56

I WANT MORE AIR IN/OUT FOR THE HEAD SET UP THEN THE VETTE HEADS OFFER. BUT AM UNSURE REGARDING THE CAM NEEDS. IT IS A HOTCOM LT4.

five7kid

iTrader: (14)

Get GM Fastburn heads, then. On the ZZ4 shortblock, they make 30 more horses than the ZZ4. And, you've got more cam already.

Go for a Performer RPM Vortec intake. And don't even consider that Street Avenger. It's the TPI of the Holley world. Get a 750 HP double pumper, that'll feed that engine just fine. You don't need a Dominator.

irocdaddy

i already got the avenger 770. will it still be good? picked it up for 225.00

can i use the vortec manifold even though the heads are not vortec style? (g.m. fastburns)

five7kid

iTrader: (14)

IMO, no.

Fastburns are Vortec-style.

xpndbl3

iTrader: (5)

sell that avenger ASAP and buy a 750dp

Damon

The LT4 HotCam is not all that aggressive a cam with 218*/228* duration @ .050, .525/.525 lift with 1.6 rockers and a middle-of-the-road 112* LSA. It's not a lumpy bastard by any stretch of the imagination. Kind of an entry level performance cam, really. Lightyears ahead of a stock cam, but nothing very radical.

ANY single plane intake on that combo is probably overkill. I think you'd need a bit more cam before I'd recommend a single plane. What you lose in low end torque you don't have enough cam to make up for in the higher RPMs. If you INSIST on a sigle plane intake I'd suggest the classic Edelbrock Vic Jr. #2975. It's about as flexible a single plane intake as you can put on a mild performance motor and I've used it MANY times over the years before there were really good dual planes available (read on!!).

The tried and true Edelbrock Performer RPM intake (air gap style or not) would probably work even better. Even with your stock heads. It's a solid choice on combos like that operating under 6500. When you swap out the heads maybe think about getting some AFR 180s or 195s and reuse the intake again.

Vortec style heads are nice, but you need a completely different intake, so factor that into your numbers when considering a head swap to anything Vortec.

irocdaddy

I am very sure I am going to go with fastburn heads/vortec dualplane high rise good to; 6700 rpm even though I won't spin her that high.

true: the hotcam is by no means a "loper" in fact, real smooth and quite at idle, but open her up and people blocks away are looking for me. I stabbed the hotcam in last year and am reluctant on removing it. I will try and mimick a zz385 here. so do tell out there, what makes the avenger 770 so hard to live with?

five7kid

iTrader: (14)

The secondaries open and close slowly compared to accelerator pedal movement. They have to open slowly or you'll get a lean bog. They close slowly because of the way the whole system operates.

Simply a terrible carb to use with a manual transmission, regardless of the price you pay for it.

Use a mechanical secondary - aka, "double pumper" - carb.

irocdaddy

did some studying am sold now on 750 d.p. heck, they are all over ebay. are they hard to tune? what jet size front and back should i start with assuming the fastburn heads and highrise vortec manifold? i want to go with no choke and mech. secondaries...

irocdaddy

update....

bought the fast burn heads and a list 4779 holley dp 750.

am looking at a holley vortec highrise right now.

what did everyone do about the underhood wiring harness? i was wondering if say "paineless wiring" made a custom harness to go from tpi to carb. i think leaving all the efi wiring there will look like crap...

am now also contemplating a higher lift solid mechanicl lifter cam.

xpndbl3

iTrader: (5)

90% of EFI wiring comes out of the passenger side, which connects to the ecm and can all be removed. Everything out of the drivers side stays.

irocdaddy

thanks. for now, was thinking of just running wires seperate of factory harness just to get things running and dialed in then approach the harness issue.