I have been doing some research on cylinder heads for my '89 TPI 350 and have narrowed it down to two possibilities:

TPIS fully ported,CNC'd,three angle valve jobb'd aluminum L98 heads

OR

The Edelbrock performers either out of the box or maybe some minor port and polish.

I figure they will cost the same (if I get the Edel's ported) but am unsure how well, even in fully ported form, the L98 castings are.

I will be matching this to either a ZZ3 or SLP cam.

Any help would be appreciated.

 

No, I'd say forget the L98 heads...TPiS wants too much for a CNC'd rebuilt head, especially a Vette head...Get a set of Edelbrock heads and have fun. Unless you're looking for an ungodly amount of HP they really shouldn't need porting, but it does help. The best Vette heads I've seen flowed 235 cfm ported (intake). Ask TPiS what those heads flow...Keep in mind TFS 23* heads flow in the neighborhood of 250 cfm STOCK. The vette heads start off at 190 or something like that, I can't remember exactly what it was...for max flow, I'd recommend an aftermarket head, TPiS is too expensive. They do have good stuff though. $1200 would be a more respectable price.

 

It going to get awfully expensive because will also need to pay or a aluminum head core. I would go for AFR 190's.

BTW I don't know if the guy is stilling them but there was a set CNC D port heads for sale on the Corvetteforum for pretty resonable 750

http://forums.corvetteforum.com/zero...030169#1030169

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Dave
86 Vette Conv.

 

I installed a set of Edelbrock RPM aluminum heads on my engine when I had a 355 in it. They replaced a set of iron L98 Vette heads that had a lot of port and valve work and had been surfaced to increase compression.

The difference was immediately noticable, I mean NOTICABLE!.

Not only did the car handle a whole lot better because it was lighter up front, but I had to adjust my driving style (not as much throttle) to keep from squeeling the tires at every stop light take off.

The Edelbrock's are CNC'd about 1-1/2" in on both the intake and exhaust ports.

The smaller port volume keeps velocity up which really helps torque. Price is RIGHT too.

There are some things to specify though. Consider what lift cam you'll be running because those heads come with two different spring packages - one can take up to .600 lift and give you 125 lbs on the seat, which is the MAX you should go with a hydraulic or hydraulic roller cam. The other ones won't take as much cam, so you've got to specify -same price too.

Decide on angle or straight plugs because some headers meant for angle plug heads won't fit straight plug jobs.

Look at combustion chamber size as this will effect compression ratio a lot.

Definitely new head bolts with WASHERS to prevent galling the aluminum and the good Fel Pro head gaskets.

Go around at least five times in torqueing them down to pull them down slowly and evenly and goop the head bolt threads with sealant (I use Permatex #2, that dark brown really gooey stuff) to head off coolant leaks.

Hope this helps.

Jake

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

 

Thanks!!