cl08

iTrader: (5)

I have searched and read and searched and read... no clear answer in my simple little redneck head.

I am building a boosted 346 w/ 317 heads (no milling, hand porting). I just got them torn down today. I am going to be buying valves, so might as well go bigger right?!!!

I know 2.02/1.57 is the largest they can go without changing the seats in the heads. What else needs to be done the to make them fit (close open NOT BREAK) correctly? An angle job on the valves themselves?

OR is the bore going to become an issue? My motor is going to be at 3.905. Is it possible the valves could clip the top of the block when opening?

Like I stated searched and could find nothing on 346's with these heads. 6.0 stuff for days but nothing defining my stupidty.

Thanks guys
Cody

transwiz

iTrader: (26)

I have a set of 317's that I am going 2.02" and 1.57" valves. I talked to the machine ship and they told me that I had to get a valve job so why not put the bigger valves in. From what I have read guys use them on 346 blocks with boost all day long.
I have a set on my 346 with huge valves,milled and I don't have problems.I have a relatively small cam 224/224 561/561.I don't think you will have any problems.I would guess that you would be ok if you didn't use a cam that was too crazy. But I have a n/a motor with no boost.

Old Geezer

iTrader: (3)

Lots of applications making insane power w/ the heads as they are now...I'd suggest you spend the $ elsewhere.

cl08

iTrader: (5)

yeah was talking to a buddy of mine at work who is bit more knowlegable on Gen III's over myself.
He pretty much said the same as Geezer, replace the stock valves with good ones in the stock size and spend dollars elsewhere.

Thanks for the input Gents

95lt1+00LS1

i have a kinda the same question i have the 241 heads currently but am wondering where to go my goal is 500+ rwhp shoud i buy some 243s and go with 2.02 intakes and 1.55 exhaust and im not sure what cam to run with yet im sure there is tons of info i just need someone with a lil more know how

Darth_V8r

iTrader: (4)

if your goal is 500+ on a 5.7L, not sure 243's or 317's would get you there without nitrous or FI

95lt1+00LS1

thank you ive been kicking around with the idea for a vortech but want to get a good base to build on for now i just want the car back together lol

Darth_V8r

iTrader: (4)

If you're thinking FI, then use the 317's, live with the lower compression for now, and you'll be ready for all the boost you want down the road. If you want NA, you'll have to go aftermarket for the heads

95lt1+00LS1

ok i thought about just havin my 243 shaved would that be good or should i just buy the 317 any thing specific i should do to the 317 or just clean em up and slap them on

Darth_V8r

iTrader: (4)

Depends on the budget, honestly. I'd pretty much always recommend porting, etc. Quick mill job to true up the gasket surface, say .020-.030 to get your combustion chamber to 70CC. You'll be ready to go for the snail-looking thingy later on

95lt1+00LS1

rite on man thank you so much for all your help your car sounds nasty id like to see that can you recomend a cam setup aswell i just talked to the head shop in virginia beach and he said 450 for everything and im happy with that.. now i need to find a cam that will fork for me im willing to put a good forced induction cam in it so i dont have to do it again might as well do it all while i got the engine out i just got my ARP rod bolts today so i will start on that this weekend still waiting on my oil pump but im just ready to get in there and get her going also should i run my ls1 intake or bite the bullet on a ls6 intake ive already got a 90mm throtle body with a coolant bypass on it and i have the injectors to support FI