tex? so if you go with ANY cam with greater than stock lift you think a 7.45" rod is needed? or just with the kind of cam Jim is looking at?

 

i got the arp studs on the way, along with some mls head gaskets, cam and springs.

seth recomended some springs not sure of the brand but the number he gave me was ex616, any idea what spring that is.

i told him i was going to get some 918's and he said they are not quite good enuff, with a 590 lift cam he gets valve float at 6400rpm.

 

I'm running 7.4 pushrods on a mid .500 lift cam. Jim is on the bubble between needing 7.4s and 7.45s. He needs an additional .05" length on top of the stock 7.38. Thats roughly 7.43", nearly right in the middle.

If he had milled heads or runs a thinner head gasket, 7.4s might be preferable. If he decides on running a thicker Cometic gasket to further lower compression, a 7.45 would be definite. If you run a big lift cam and have heads milled for compression, you've moved both in the same direction, in effect canceling out some of the change.

 

I'm running 918s, but I wouldn't trust them for a really big lift cam. Do you know if the ex616 are duals? I'm not going to risk a single spring on a built motor with expensive heads. A couple of weeks back, I helped a friend tear down his LS1. 2 of the pistons had major valve impact smile marks from broken comp 941 springs. The other pistons had some very light marks just from valve float.

GM stock 6L MLS gaskets?

 

Parish,if the kit uses an adjustable wastegate you should be able to run any amount of boost the turbo is capable of producing(more than you might expect),the smaller tubo will develop boost more quickly at lower rpms(little or no turbo lag) while the bigger turbo will take longer to produce more boost at higher rpms(turbo lag)with a big surge of power at high rpm.Id be a little hesiatant about going bigger than what's suggested.

 

from looking at the sponcers lists of parts they only seem to have shorter pushrods, nothing longer, i think stock will be fine, might get some better ones with the 409 though.

i dont think they are double springs but they could be, i will have to get more info on them. he did say they fit in the stock pocket.

 

did a search on EX616 and this is all i could come up with. here

 

hey whitt, i all ready have the boost controler installed, all i need to do is spin the **** and wamo, any boost i want. i am thinking with the 6.0 i can probably run 9-10psi on 92gas, then 12+ with some good gas

 

That gives me quite the spring!

Jim, too bad you and I live so far apart, I'd love to help out with this motor / turbo project. I have a good feeling about this one. It makes me want to build for low compression instead and go turbo. I won't spend $5k on a turbo plus the $$$ for building a forged motor, so its not likely going to happen for me (at least any time soon).

 

I was told that if you upgrade the valvesprings more than the 918s you need to run Comp R lifters because the added spring pressures will colapse the stock lifters.