Do any of the aftermarket comanies make a head for perimiter bolt valve covers. I know I would only have to change valvecovers but want to keep the 98 look. I've tried the search but can't find anything.

 

i don't know of any compaies that do, but i am sure your local automotive machine shop could hook that up, it would require measuring, adding screw bosses in the right places, and then drilling and tapping them. i can't imagine it being too difficult.

 

only thing i can think of is getting some 98 perimiter heads and get them ported.

 

All the benefits of these new aftermarket castings are incredible. I thought about porting 98 heads but think it would be better to have an aftermarket casting.

 

My ported '98 castings are doing just fine

 

Not saying ported heads aren't fine but look at the solid numbers being made with all the new heads. Look at the torque curves and peak numbers. Much better IMO

 

Yeah your right aftermarket castings are where tha butters at.
can't wait till i can afford some 11* ET heads.
BTW why do you like the look of 98 heads? i HATE taking thgose damn valve covers off.

 

somebody does or did in a prototype or production aftermarket head that had both the centerbolt and perimeter bolt provisions, i just cant rememeber who

 

I have a set of ported 98 heads for sale.

http://www.ls1miata.net/gallery/album01?page=2


http://www.ls1miata.net/gallery/album01?page=3

I have them listed in the for sale section.

 

i guess the machine shop route on center bolt pattern heads is out of the question? any center bolt head can be converted to perimeter style with a little, and i mean a little, work. any metal working shop that is good with aluminum should be able to do it fairly easy. call a couple machine shops and/or metal working shops in your area and see what they can do. you'll be suprised with the amount of craftsmanship some of those guys have. just trying to help, though. its your car and your money.

 

Sounds like this may be the only alternative. I had given this some thought but was kinda waiting to see if someone was gonna make these heads. I know that edelbrock had talked about it but that was before the release of their heads.

 

Yeah your pretty much SOL cause everyone i know hates the perimiter heads. so i doubt they will make a whole seperate casting for them.

 

i know that patriot has some perimeter style heads. they are 899 i believe.. also im not to sure on this one but if you call AFR they might be able to make them perimeter valve cover style.. i think its on option to have both styles.. but then again im not to sure on that one so dont quote me..

 

Patriot Performance has LS1 Stage II Perimeter Bolt Assy heads for $1095/pair. Part# 2007.

 

Patriots are still an oem casting.

 

Well, that is gonna be your best bet. They are the only ones that I have heard of that offer "perimeter performance" if you will. Plus you will only be toying with the fact that you would be losing 10 rwhp at the most probably on a naturally aspirated motor unless someone like ETP or AFR made one. The demand is not high enough. Most people would just assume to get rid of those heads and just replace coil brackets and valve covers for a small price and get a newer style head.

 

I have PRC permiter bolt heads

 

How long have you had those heads? And where from?

 

Couple months. And from Teaxs speed.

 

That was what I thought. Is it advertised on their site?