Just finished dropping a 355 into a 1984 Z28.

The engine is 4 bolt main bored .040 over
The heads are dart stock replacement heads with 1.94 valves. (Intake runners have been opened up next to the push rods to 1.08 inches and both the intake and exahast bowls have been opened up substantially and blended to the valve seats. the intake runners are also matched to the gaskets and then everything in the runners was blended together.) The intake ports are about 195cc.
Cam is a little better than stock with about .475 lift on intake and .450 on exhast.

The Car has 3.23 gears in the rear end and an automatic transmission.

So here are the questions
What will it do in the quarter as it is?
What would it do in the quarter if I changed to 3.73 rear end gears?
And about how much horsepower should this engine make?

Its all put toghether now and it does not seem to have the pull I thought it would when I nail it froma standing start. Afte 2500 RPM it goes like stink.

I would really appreciate answers to my questions and any suggestions you might have to improve the stop sign to stop sign performance.

 

what type of induction and exhaust are you running. motor sounds alright, probably low 14's high 13's with the 3.73's, depends on a lot of factors. you arent running the stock q-jet, manifold and exhaust manifolds are you?

 

Yeah Stock 4 barel intake, quadrajet and stock exhaust manifolds matched to heads and knocked out the flaper doey thing that used to be hooked up to the choke. Don't want the headache of the floor mats burning off because of headers and didn't think that there would be many ponies to be gained by dumping a $1000 canadian dollars into an aftermaket intake and carburator.

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White bone stock 87 RS

 

If you're gonna go through all the trouble of investing a bunch of $$ in, building and installing a high performance engine, putting headers on there is just details. The stock manifolds, as well as the rest of that exhaust system, are junk and the numero uno bottleneck on thirdgens. You're throwing away a ton of HP by keeping the highly restrictive stock exhaust system. I'd invest a little money in a better intake as well. You can pick a used edelbrock intake on ebay for less than $100.

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Red '87Formula Firebird
-mostly stock 5.0L LG4 w/cowl induction setup borrowed from '83 TA and T5 tranny.

My newest Ride:

'85 Silver L98 Corvette w/4+3 manual tranny. not bad for $3500.

[This message has been edited by RedFirebird (edited November 29, 2001).]

 

do you have to run smog? if not, a set of ceramic coated shorty headers are available for our cars through hedman. they are 230 so they arent too expensive, and wont get nearly as hot as painted headers. also, your stock q-jet is not nearly up to par with your engine, as isnt your manifold. change these and you could see massive horsepower gains.

 

I'd say that it would run about a 18.4, maybe 18.3.........just kidding.

 

double post

[This message has been edited by Violate 3.8 (edited November 30, 2001).]

 

Yes I have to run smog. I have to get E tested in the summer after that though the car is 20 years old and I will not have to be tested again.

Will the 3.73 gears make much of an improvement over the 3.23s?


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White bone stock 87 RS

 

yes the 3.73's will make a sig. difference. Right now though, you've got a healty engine breathing through a straw.

Anthony


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previous ride: 87 Camaro LT
350, A4.Comp Cams 268H, Edelbrock Preformer intake, Hedman Headers and y-pipe, gutted cat, No AIR/smog pump. 14x3" Open element K&N, Q-jet w/ D hanger and DA rods, adjusted AV spring tension and quick can.

Current ride: 1992 Camaro RS, K&N, Flowmaster, 305, T5, Black, T-tops, 84k miles.

 

go away, nobody likes you.