are they direct swap (with their rets and lower seats) in stock head or is there any modification needed except thinner valve stem seals, to clear inner spring ? are stock valve keepers reused or these rets requre some other ones ?

also interested in feedback about how they perform with S2's, any good ?

 

talking about SPR-M1007D

http://www.supertechperformance.com/...n=ivalves&id=7

wouldn't it be a bit overkill for S2's ?

 

Depends on how high you plan on spinning your engine. I use supertech duals (have been on the car with HKS280s and Kelford 272s), but my fuel cut is 9200 RPM.

l8r)

 

Anyone ?

I'm also interested ....

 

let's say two cases, first 2.3 stroker revved to ~8000 and second - 2.0, revved 8500-9000

both with S2's

 

bump for input

 

yes they use the stock keepers and they come with stem seals. They work well with any deccent cams.