I have a 87 Trans Am that I installed a 350 into over the summer. I picked up some stock cast iron L98 heads off a 92 Z28 casting numbers 14101083. I'm looking to install 2.02" intake valves and 1.60" exhaust valves on these heads and was wondering will it make a difference in performance and if it can be done. I don't know much about this. I think the stock valves are 1.94" intake and 1.50" exhaust right? The reason I'm looking to do this on the stock heads is I already have quite abit of money in them. I had larger springs installed, screw in studs with guide plates and some porting done to them. Did any one else do this? Any ideas on what I would expect to pay at a machine shop for them to install the vales if I supplied the parts? Is there any way I can find out some info on these heads like the cc's and such. I was wondering if there was a site on the net somewhere or if any knows. Sorry it's so long I just want to know if it would/could be done and if it will improve the performance. I already have hooker headers and a exhuast system installed. And will get a Edelbrock TPI Intake for this also. Thanks

 

The heads would need to be cut for new seats to allow for the bigger valves.

The heads check in at 64cc I believe.

To be honest with you I would just save my money up,and get a set of edelbrocks,or whatever down the road.

Its just not worth putting alot of time/money in those heads.

If price is a factor you could get vette heads have them cleaned up/minor pocket porting...2.00/1.56 vavles,they will run good for you.

With those heads,intake mods,exhaust mods,mild cam,ect...you can run easy 12's.

 

I was thinking of doing the same tihing with my old heads so when I build my 350 for my firebird I'd have some good heads. But I went to the machine shop to do the work on the heads and the total cost would have been $880.00! Heck so a few more dollars I could have some good NEW ALuminum heads.
If you want to save money now port them and put them on for the time being. Not the best but it'll work for the time being.
Lots of Luck

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89 IROC 350 Auto
Custom DUAL Exhaust
Edelbrock Performer 6085 Aluminum Heads
ZZ9 Cam
TPIS Level 5 Chip
14.01 @ 97.0mph with 2.77's gears and a bad ignition control module!
And Free mods.

 

Excellent advice!

I did the same thing in 1999 with the stock iron heads on my 86 Vette; screw-in studs, guide plates, angle milling, porting, etc. only the pull them a few months later and install a set of Edelbrock's.

Out of the box, the difference was instantly noticeable. Throttle response was much sharper and I actually had to change my driving style to keep from squealing the tires coming off a traffic light. Your handling will improve markedly too.

My advice: don't put any more money into those heads. Try sell them to someone who is looking to step up from what he's running.

I've got a lot of aftermarket head flow numbers I can send you if you're interested.

Jake

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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

[This message has been edited by JakeJr (edited January 20, 2001).]

 

Sorry,

I'd just pay the man the $400 bucks for a pair of Vortechs and slam them on out of the box....

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87 Z28/89 vette 383TPI roller cam/700R4/vetteOEM 2K TC/MSD 6A/SLP stainless headers/edelbrock cat back/Optima/TTops/an angry squirrel.

86 Fiero SE 2.8V6/5SPD/turbo/2nd angry squirrel.

Runs on peanuts!

72 Pinto Wgn Version 3.0 /85 5.0L HO/AOD/ lowered/Shaved/Tinted/Optima/WHITE