LS Shims

[gectek]

ok so i looked through posts but didnt find what i was looking for. on the isky shims you have to machine around the valve guide/spring seat right? so on the LS shims that alot are using i heard you have to drill them out...is that correct also? if so how much do you have to drill them out to and also do you have to trim the OD down on the ls shims?

[SappySE107]

Just the inside on the GM LS shims if your guides are the larger diameter. Otherwise they drop right on.

[gectek]

ok and no one has had any problem with the bottom of the spring walking around on the flat shim?

[SappySE107]

It doesn't have anywhere to go really. Its right around the guide. Same with the isky shims (they fit all guides, but you have to machine the seat pockets). I like the isky shims but they aren't cheap.

[gectek]

has anyone looked at the new ls seats that comp offers. chevy high perf mag of march 07 has a high revving 403 that uses the comp 26918 and the steel locks with titanium retainers and ls seats. when i put in the pn in comp it comes up as nothing, so maybe they are too new? then pn is 4705-16 , but i bet they could be had in only 12 units seeing as how they are for the 26918 spring, and also the clearance for the guide is .570 in to fit over the guide, does that sound like it would work? they are a more positive style seat like the isky, but i dont think the head would have to be machined hopefully

[SappySE107]

Ill order them tomorrow and see how that goes. Might be cheaper for me to just order 16 at a time.

[gectek]

so any news on the ls seats yet?

[SappySE107]

I didn't order them because they are .060 thick. The specs are in the new comp catalog though and they won't require any machining. I have 2 sets of the isky seats so I don't need any more .060 thick seats now.

[gectek]

cool, so i have mine ordered, ill post pics when i get them. you want any actual measurements?

[SappySE107]

Nah, i got the measurements from the comp book. Pics will work