Hey guys, I have an 85 vette with a zf6 swap and I want to build the 350 in it up. Any good combos? I want to run a carb, I plan on doing a top end rebuild but still pulling the motor out. I know I'm going replace the fuel pump, what else would I need to do? Thanks

 

Bob,

What's your budget? Hp goals? Just a cruiser or do you track it at all? Auto or Manual?

With answers to those questions you'll get more response.

 

I've got about 4k, I want around 500 hp, it'll mostly be a cruiser but will see the track, it's a zf 6 speed

 

track means... road racing, drag strip, or combo?

 

What is your current power level? Is it a stock motor right now? What other parts are stock? (trans, rear end, ect)

My expereince is that with a $4000 budget, you won't see 500hp on a NA 350sbc. You'd need another $2000 minimum I believe (probably more) and then you'll have an engine whose drivability is compromised. An LS engine can get you to 500hp with less radical parts and better drivability, but $4k won't be enough to make it all work in your car.

If you'd settle for 400hp and your current block is good I'd suggest a good set of aftermarket heads (AFR 205's come to mind) milled to bump your cr to 10:1 with a complimentary cam that can make the most of those heads air flow and still have good street manners with a good 750-830cfm carb.

With the LS motors getting all the love the prices for sbc stuff has come down. You'll probably use all of that $4k budget to make it all happen especially if you need to machine your block at all, but you'll be close and should end up around 425hp at the crank which is pretty zippy.

 

It's going to be a combination of tracks. Right now it has a beefed up drive train with a black tag zf and a rebuilt/beefed up Dana 44. The motor was recently rebuilt about 5k miles ago, but it wasn't done very well(a shop did it) it has computer problems so I want more power its very weak right now(about 250 hp) they put a cam in it but didn't tune the computer. So I pretty much want a street machine that'll go to a combination of tracks in the SoCal area.

 

Where in So Cal are you?


http://www.airflowresearch.com/chevy_dyno.php

Gives you some ideas

 

Drag or road course? Rear gearing? What was done to the engine, and did they give you cam specs? What heads are on it now and what is the compression ratio of the engine?

Scour the Internet and find a reputable shop that has expereince in doing what you want. It might be well worth finding a good shop that will look at what you have and make suggestions. If they do a compression and leak down test and those check out and you can answer the above questions you will have a place to start.

You'll find that getting a 400-425hp reliable good driving 350 is relatively easy but will probably go over that $4k budget. Getting to 500hp without a power adder is going to add a fair amount of $ to it as well as make it not that fun to drive on the street and costly to maintain.

If you are at 250hp and you get that critter to 425hp, unless you make it a dedicated track car you will be well pleased. Gearing if a manual, or a stall if an auto can wake it up a bunch also. The Internet is your friend. You do have to wade through some bs, but you'll find that a good set of heads will be your best bet to reach your goals and a cam matched to that and your gears and intended use. Find a shop with lots of customer recommendations and make it clear what your goals, budget and time frame are. Have fun.

 

I'm in the chino/Ontario area

 

It's running 3.73s, has stock heads. They never gave me the cam specs. I'd honestly be happy with 400 but I'm trying to get the most out of it. It'll mostly drag but sometimes autox. It was just a simple rebuild bored .30 over

 

Unless its a track only car smogs an issue
What about a used superram an afr head and a say, 10:1 (or a little more) shortblock? that will get you moving just fine and pass the sniffer/inspection. Would be great for autocross too tons of torque.
May go over budget some unless you have a sound shortblock you want to use

 

I know several people so smog isn't going to be a problem for me. I hate California's emission laws! It already has a gutted smog system so technically it's already going to fail the vusual inspection.

 

That link to afr is a good one to review. The pkg just utilizing the 180cc heads would make a world of difference. I like the edelbrock rpm plus intake manifold if you're going to go past 6000 rpm's.

Go for street tq instead of a peak hp number and you will be much happier. Not knowing what the cam specs are a bummer as that tells you what your rpm range is and matching your heads, cam, gears and intake is how you come up with a killer combo.

With it still needing tuned it might be tough, but at what rpm is the engine all done? You may start with a good tune and go from there. The 3.73's are a good overall gear. If I was you I'd probably start with finding a good shop, get a good tune so you know what you have, then just possibly find a good set of AFR 195 heads and try that using your existing cam and fuel injection. Unless the cam is way mismatched you might be very surprised and be under your budget to boot. If you are patient you can find some heads with all the valve train used for $1000-$1300. That's where I'd start. Headers and exhaust if you don't already have that. Unless there is a limiting factor I don't know about, you should be in the 350hp range and jumping a 100hp should put a huge smile on your face.

 

at what rpm is the engine all done?

It literally dies at 5,200 it just drops the power off and you feel the stop of acceleration. I have a buddy that's really experienced in motor builds he's going to help me find parts, tear down the motor, and tune it. He's done both efi and carbed motors. The reason why I don't want to keep my efi is the fact that I'd rather not deal with the breaking parts and my engine wiring harness has been damaged by a faulty battery before I'm just waiting for the day it goes out
on me

 

How are you going to get this to pass smog?

 

CA. Very good question. In the long run, I would think unless you are prepared to deal with the CA nonsense or the fuel inj is going to limit you (don't think so for 400hp) you'd be better off to repair that and pass on the carb.

Answering the question of why the engine is all done at 5200 is the place to start. I'd think you want another 1000 rpm to get the most out of a set of aftermarket heads.

The right cam, heads, exhaust and tune along with making that efi work right should keep you in budget and gain you 75-100 hp.

 

Long tube headers if you do not already have them.
Good exhaust.
zf6 is good because you can run a bigger cam and not worry about a stall converter.
Hopefully you have flat top pistons in your rebuilt short block.
AFR 195 eliminator heads,64cc chambers,l98 angle plug.
85 is not a roller block so on the cam just a comp cams 292H magnum.
A regular edelbrock performer 2101 for ease of installaion and hood clearance. Performer RPM would be preferred but a lot harder to fit under stock hood.
Holley 750 double pumper for max HP but a 650dp would be more responsive.
A basic 400-450 hp combo

The AFR heads ARE the horspower. There are other good heads out there though.

 

Thanks! That sounds like a good kit/combo. I'll me checking prices now 👍

 

Smokey Yunick who knew more about small block chevys than anyone , said to make real power with a small block chevy, the engine needed three things:

(1) six inch rods
(2) 2.05 inch diameter intake valves; and,
(3) two piece top ring

 

Long as you dont get a notice to go to a star, or test only youre good.
Thing is cars that vintage get called in "randomly" ie too often


one more reason I was convinced to stop playing with C4s....couldnt go fast as I wanted and not have the hassle.