Cewofford

Ok so i have read hundreds of posts and have not found exactly what i am looking for. I acquired my 1991 z28 about a month ago. It has 305 TPI with 700r4. The transmission was rebuilt approx. 10,000 miles ago and functions well. The 305 runs well has good oil pressure but smokes at startup and under hard acceleration. I have obtained a 1982 4-bolt short block that is bored 40 over and has less than 200 miles on it. I prefer to keep the tpi setup even though others do not agree. I can change that later if I so desire. My plan is to pull 305 and remove heads for valve job. Bolt heads and intake to the 350 replace cam add headers and use belt system on 350. I realize a tune will be needed as well as possible injectors. I would love to have 300hp at the rear wheels. I have been told that using my 305 heads could bring compression up to maybe 10:1. Which is where some of my power will come from. Now the question> How feasible is this build? Will I need a different flywheel? Is there anything else I will need(besides gaskets)? Is my goal obtainable? What is the suggested cam( flat tappet)? Three angle valve or standard valve job? The purpose of this car is a little more pep along with reliability. Plan to keep this one for awhile and will be painting later on. Any other suggestions would be awesome unless its swap an LS, LT, or viper motor. I cant afford that trying to freshen up the powerplant and have a lil fun. I should have the motor Friday.

vetteoz

iTrader: (13)

Sounds a goer if you have calc compression correctly

Yes you will have to buy a new flywheel to suit your older style 2 pce RMS crank in the '82 engine because the 1 pce RMS flywheel from your 305 won't bolt up

BlackenedBird

iTrader: (5)

Those 305 heads have small valves & flow like crap so I wouldn't use them if you have the option not to.

Cewofford

I've read the heads are way better than any truck head I could find. Don't have $1500 to spare for new heads and read I could have the grinded to 1.94/1.60. If that would help that much. Plus the small combustin chamber could give me a higher compression ratio. I am right on this or way off base.

five7kid

iTrader: (14)

Small intake valves, yes. Flow like crap - not sure what kind of brownies you eat.

1.94" intake valves, 1.60" exhaust valves, basic do-it-yourself bowl clean-up, you're looking at higher compression from heads that will out-flow stock L98 heads.

BlackenedBird

iTrader: (5)

Brownies? Never heard that kind of expression. Your not thinking of "special" brownies are you?

I knew the L98 don't flow all that well (not a news flash), but I've never heard of the 305 heads flowing that all that good either, but OK.....If you say so.

Cewofford

So local machine shop says compression will be too high. Yet number of friends with motor building experience claim that the 305 heads on the 350 could provide manageable compression and good performance on premium fuel.

five7kid

iTrader: (14)

The 083 L98 heads and the LG4/L69/LB9 416 heads had the same ports. With 1.94" intake valves, the only factory production heads that flow better are Vortecs.

If the 350 has dished pistons with more than 10cc's, the 58cc 305 heads will bring compression right to the same point as a 350 with factory 64cc heads and flat top pistons.

Cewofford

I know they are new factory pistons. And they are dished not sure how much. Thanks five7kid. I am hoping for 10:1. I'll do the math when I know for sure.

Cewofford

Also can get a good deal on 1 5/8ths primaries headers with y- pipe. Are those primaries big enough or should I hold out for bigger?

InfernalVortex

iTrader: (4)

out of curiosity, how do the 113 corvette L98 heads compare? Arent they the same ports too?

vetteoz

iTrader: (13)

Good enough for what you want to acheive

Cewofford

Ok so my rear diff is open. I've been told that all trans am had limited slip. Is this true? If so I can pick up a 1991 minus engive and tranny but I have to buy entire car for $200. Problem is there is no title so I can't get rid of it once I remove the rear axle. I told him if it's posi I'm interested just not sure what to do with the rest of the car. I guess I could try to part it out. I think the gear ratio could be different also since the trans is 5 speed and my car is auto.