Cascade Crew

[jakemk8706]

right now i am in the process of building a 350 to replace the 305. it is my first motor build so i am not trying to go over the top with power or top of the line parts i just want to get a motor build under my belt before i go all out.

the deal is i already have a set of "462" heads. i believe those have 2.02 and 1.6. so for a christmas gift my dad got me this cam package

http://store.summitracing.com/partdetail.asp?part=CCA%2DK12%2D242%2D2&autoview=sku

he was told this would work well with those heads.

recently i acquired a set of alluminum corvette heads. i think # "141" or something. so i was wondering which heads would work better with this motor. i know that my stock intake manifold will not match up with the perimeter style heads but i wasnt planning on keeping the stock tpi. i want hsr, but im not sure if holley makes a hsr that will work with older heads.

so which do you guys think i should go with???

[izcain]

The link doesnt work there bud!


If it was me and I had a set of iron heads and a set of aluminum heads side by side I would go for the aluminums any day and save yourself some weight. maybe spend a little bit of time reworking them.

[Quasi-Traction]

What's your bottom end look like?

Stock 350 roating assembly? Flattop pistons? Dished? More information may be need to help advise you properly.

Find out if the 141 casting aluminum heads are for a Gen I or Gen II SBC. I don't think the GM fastburn (aluminum Vortec) have an actual casting number, so there shouldn't be a concern there. If they're a Gen II, you won't want to use them. If they're like L98 Vette heads, I think they have 58cc chambers, so keep that in mind with your bottom end. If you zero-deck and go with a piston with no dish, you're gonna have super high compression. So that means premium only, and you might then have to retard the timing a bit to keep from detonating. Aluminum heads are generally more forgiving to that, than iron heads, so you might be okay there.

462's are a good iron head in factory form, and your compression will be lower, assuming you use a flattop and a zero-deck. I didn't get your cam specs (link didn't work) or see if it comes with springs, or if its just a cam/lifter set. If you exceed about .485 lift, you may have to have your valve guides cut down, and possibly go with screw in studs. If you do the studs, you'll need guideplates as well. Might want to double check your install height and seat pressure with the cam card and see if you need springs or not.

[Twilightoptics]

In your case choose your heads based on compression.

Get more research. The 462 heads if they have 2.02/1.6 valves are probably reworked and have a different chamber volume than they did originally. Plus you need to make sure the 462 heads have been drilled for the accessories. Don't bother with them if that's the case.

If the aluminum heads are indeed 58 cc you'll need to be real careful with your build. Don't know if you're buying pistons or whatnot.

You kind of want to build everything as a unit.


The HSR will fit Pre 87 and post 87 cylinder heads.

Intakes from both sides will work on the other if the 4 bolts in the center are drilled out to the appropriate angle.

[jakemk8706]

ok. try the link again.

so from what i gathered, the 462's are good unless they dont have accessory wholes, and i do beleive they aluminum ones are l98 vette heads.

also the block and rotating assembly i got for free from my dads friend, and it seems this is a stock rotating assembly. i ran the vin number on the block and it was assembled i beleive in the mid 70's.

if you have more questions please ask. cause the more you guys can advise me the better.

[Twilightoptics]

make sure the rototating assmebly is going to work in the block. You'll need to mic all the clearances and possible have machine work done. You might have to bore the block and buy new pistons which opens up even more doors.


I'd go the vette heads for sure if you get the rotating assembly together and it's flat tops or dished pistons.

[jakemk8706]

i have already had all the machine work done so the whole bottom end is ready for assembly. so thats why i ask which heads i should go with that will work best with what i have already.

[Twilightoptics]

So what CC pistons are in it and how far down in the hole do they sit at TDC?

[Quasi-Traction]

When they assemble the bottom end, they should mic everything and tell you how far down in the hole each piston is. Your deck height is the distance between your higest piston and the surface the head mounts on @ TDC of the stroke. Also if this is a mid 70's block, and stock cast pistions plan on having about a 12-20cc dish plus a few more cc's for you valve reliefs.

Whoever did or is doing your machine work should be able to give you all the information you need.

I believe the term is "blueprinting" a block.

http://www.empirenet.com/pkelley2/DynamicCR.html

Paul sent me this a while ago. Great resource for calculating your dynamic compression ratio.

[Twilightoptics]

If he did the assembly himself the machine shop wont have a measurement and he'll have to measure himself.

[Quasi-Traction]

[Twilightoptics]

If you have an accurate set of dial calipers that'd work too. But actually as Chris said, assemble the motor then drag the short block down and have them measure. To do it right it helps to have a dial indicator so you know you're 100% at TDC.

[jakemk8706]

my dad has all the tools to make accurate measurements and all so im not worried about that.

i guess i just have a little more leg work to do... no big deal,im not really in any rush to get this done.

[Schultzy89GTA]

get it done before january and then you can dyno

-Schultzy