Having had the rebuild for the stock carb on my 87 Z-28 (305 4bbl, t-5 trans.) ( fail miserably, I'm looking to go with either a Holley or Edlebrock and while I'm at it, I'm going to replace the intake manifold. Not sure if the 305 is standard or hi-output version, or even the oddball LU5 (due to the cover on the air filter element, it distinctly says "cross-fire", though dude who had it before me might have thought it looked cool.) The 8th value in the VIN is an 'H' if that helps determine what type of motor I have.

What I want to know is what the ideal aftemarket combo of carb and intake manifold is. Most of what I have seen from the company websites is that the carbs and manifolds are not compatible with 87 and later engines, only til about 1986. Appreciate the help and advice in advance.

P.S. I know someone is going to say drop a 350 crate in there and save your time. I'm asking nicely for y'all to save your time with that, it's not a feasible option at this point in time. Also, I'm going to assume that this model year is EGR (no idea what that means.)

 

650CFM with Annular boosters holley, demon, quick-fuel, AED. I recommend AED.

Edelbrock Performer Air Gap.

Air gap is a cooler running intake, run annular boosters with high booster signal to negate the negative effects of running cooler intake.

 

And an annular booster is?

 

Its a higher gain type of booster. Do a google search on carb booster types and signal you should have a miriad of information at your fingertips.

If you have or want to switch to carb this is information you should know.

 

OK. Thanks. Really just getting into this from a mechanical standpoint. Not really mechanically inclined but I'm trying to learn.

 

Don't forget that you need a non-computer controlled distributor to replace your current computer controlled one when you ditch the computer controlled QJet carb. Factor that into your budget as well.

Performer EPS with a smallish Holley or Edelbrock vacuum secondary carb would be my recommendation. Newer computer-designed intake than the old base model Performer (or Performer air gap). It's the "little brother" of the Performer RPM intake and well suited to near-stock applications. And it will still clear the stock hood no problem in a 3rd gen. The RPM is really tight on hood clearance in the 3rd gen.

No chance your car had CFI. Not an available option in 87. I think 84 was the last year it was offered in a 3rd gen.

 

I don't like vacuum secondary's with a manual. Never did. I like to have full control over the carb when I have full control over the trans. Ive driven both ways and mechanical secondarys>vacuum every time with the manual.

Trust me annular booster 650, and an air gap or EPS as damon said. You will have a lot more fun with that type of setup.

 

Nothing wrong with buying an intake and carb for a 305... you can use those on a 350 just as easy. If you have to buy pistons - then you get a 350.

Anyway, if you can take the time to tune it, a double pumper is gonna be better. If you're a slap it on and turn a screw a few times type guy like most of us, you might be better off with vac secondaries.

I drove around with a poorly tuned double pumper for years and finally dug into it and started trying to tune it, made an AMAZING difference in drivability and power and throttle response. I can't believe how crappy the tune was, and that I was willing to accept it as "oh it's a carburetor, it's gonna be like that..."

In my case I just had to up the squirters 7 sizes, up the jets 3 sizes, and get the idle circuit and float levels set properly. I just never went through the trouble to mess with jets and squirters until recently. Just gotta mess with it - you'll get the hang of it.

Also, the annular booster thing... it's nice, but dont fret too much over that. Any regular cheap/common as dirt 4777 double pumper is fine for your engine. 650 cfm may be a bit much, maybe go with a 600. But you can tune a 650 to work for you. The Air gap intakes are a gimmick mostly for looks, IMO. After the engine has been runnin 10 minutes the whole intake is the same temperature anyway, negating the whole purpose of the "Air gap". Just makes it run worse when it's cold since you're gonna tune it to run well when it's at operating temperature. Performer RPM intakes have the same runners as the Performer RPM Air Gaps, air flow is the same, just doesn't look as "neat". They're higher rise than the factory intakes, so you may have to work around that, but they are still dual-plane intakes, so tehy'll work well on a stockish car still. My cammed 350 with an RPM intake can cruise the interstate at 1300 RPMs easy.

 

Will the airgap with a holley fit under a stock hood?

The stock hood on my friends 86 TA with an edelbrock 750 and air gap did not but he did not have a special air filter.

 

It should fit with no problems I have seen many people running them. I personally run a Vicjr highrise but I have had no less than a 3" cowl since I had the car. Dropped base air cleaner, or a shallow element should be fine.

 

Cool just wondered mostly because my regular RPM performer and 1 inch spacer with a regular air cleaner does not fit.

 

Get rid of the 1" spacer and get a drop base for the air cleaner. will work perfectly

 

zuku3014, you're really barking up the wrong tree here. Street driven car, the only legal carb is a computer q-jet (don't tell me you don't have "emissions" where you live - it's federal law, not state or local).

Above that, the computer q-jet is the best street/performance carb system you can possibly have. If the computer q-jet can't handle your engine, then your engine isn't street legal for other reasons. Since yours is "stock", it doesn't make a lick of sense to go with an aftermarket carb.

In both the short- and long-term, your best option is to get the computer q-jet fixed up, either send it off for a proper rebuild, or buy a rebuilt carb. If you want, go ahead and get an emissions-legal intake manifold while you're at it ('87-up versions are readily available from Edelbrock, Weiand, and Professional Products). It won't make as much difference as exhaust upgrades, but if you really want to do an intake, that's the way to go. You won't need to buy a new distributor either this way.

If you really, REALLY insist on going with an illegal aftermarket Holley or Edelbrock, then at least get a double pumper Holley (or similar design from another brand). This is because you have a T5. Do NOT get a vacuum secondary Holley type carb.

 

im one of them, you need a 1.5" drop base air cleaner. you can fit a 3" filter if you lose the spacer. or a 2" filter with the spacer.

you also have to make sre the carb stud/nut doesnt stick up past the top of the lid. or itll hit the hood.

 

If I ever go back to a stock hood I will do just that. Sometimes I think I might get a few more people to run me if I had a no cowl.

 

i hate to be the guy to say it, but get a better motor if you want to go faster. no need to dump money into a 305. just a waste of money & time. been there, done that. you might be mad, but its a truth. save your money.

 

Performer RPM = same runners as Performer RPM Air Gap. It will flow exactly the same, and it's exactly the same height.