I know everyone says go 350, but I have a 305 already and I'm just messing with the possibilities for now. I've been thinking about either building it 305, or 335.... I've seen the S/R Torquer 305s, but they talk about shrouding with the valves... what EXACTLY does it mean by that, and why is it bad? I found keith black 10.8:1 compression 305 pistons, that was for a 58cc head. Are there any other options out there? How much can I effect compression numbers with headgaskets? Someone else mentioned Protopline 23* 180 heads? What other good heads are there out there for the 305 still available? What cranks are there for the 305? I recall reading that the 305 and 350 cranks are the same, but the 305 is lightened... so can I get any crank I want? What rods do I need? I'm just a newbie here and I'm looking for some guidance... thanks.

 

It's your money

https://www.thirdgen.org/techbb2/sho...hreadid=218374

 

like rb has said you'll be spending your money to buy a bullet to shoot yourself in the foot with. you'll work harder and spend more for less with a 305 than a 350. as an added bonus you can build the 350 and drive the car while you're doing it. shrouding the valve means the valve is too close to the side of the chamber to allow good air flow

 

as ede said, shrouding means the valve is too close to the chamber. if you search for stuff on 305's, there have been many discussions on whether or not a 1.94 valve is too big or not. i personally think just by visually looking at it, it appears too big, but in defense of those who think it's fine, GMPP and World Torquer both put 1.94 valves on their heads for the 305. i know a lot of guys with Torquers that haven't had any real problems with them, but nobody that I do know that has them, has had them for a real long time, so i can't really say if valve shrouding will be a big problem down the road. If you really want the best performance, i'd definitely get the Torquers and get 'em ported real well, cause if you do that and match 'em with a good cam and some intake and chip tuning mods, i can see 300 HP easy for you. but if you do that, you can kiss your fuel economy goodbye, which IMO is the real only reason to keep a 305.
if you want to keep good gas mileage and get decent performance, i'd go with zz4 aluminum heads (58 cc) from GMPP, but you'll have to do a EGR delete, cause they don't have EGR passages. they'll work REAL well with those high compression pistons, though you'll probably have to use thin head gaskets as well, cause the heat dissapation that the aluminum heads utilize will drop your compression. and also obviously get rid of the stock cam, it's crap. once again, go with comp or crane if you want to go all out, stay with GMPP if you want to retain drivability.
really, i'd only build the 305 if you're doing most of the work yourself, cause you're gonna have to do quite a bit. you'll probably need a new fuel pump, and definitely a new PROM. and if you go zz4 heads, you'll have to do the EGR delete and some compression mods to get the best out of 'em (unless you just get them milled a few cc's). i modded mine for two main reasons:
1. I got a friend who can get me GMPP pretty cheap and owns a shop to work on it in.
2. To give the 305 some kick while it lives, cause after it blows up, i'm moving on to bigger & better things (5.7 L LS1/LS6 ).
if you're paying for labor, or you're serious about performance, i'd ditch the 305 and get a 350 or 383.