im building a 400sbc for my z28 and im wondering if these heads will work there a 64 cc camel hump head with acc holes and a closed chamber i know i have to drill steam holes but will the cr be to high for regular unleaded?

the engine has stock dished pistons thanks!

 

If they have the bolt holes, they're not really a "closed" chamber.

They will work. On a stock 400 short block, they should give around 9½:1.

 

thats good news, the casting number is 370 cant find much info on them, 1.94 1.50 valves

 

my advice would be to have the combustion chambers measured to see if they are indeed 64cc's. I can't find any small block head with the casting number ending in 370. Also do the math on your static compression it varies with piston dome or dish cc, how much the piston sits above or below the deck, head gasket thickness, etc... I had a 400 with flat top pistons at zero deck height and a felpro gasket with a 041 casting head and came to 11 to 1 compression. Always good to check.

 

370 - 3973370 - was a service replacement head for the 69-70 350 4-bbl. Similar to the 492.

 

great, looks like im picking them up saturday!

 

heres the heads, fresh rebuild, spacers under the springs mild porting.

 

last one

 

If I remember correctly they are 68cc heads, 64cc had a small quench area next to the spark plug, you can see yours are laid down slightly by the plug.

Still good old heads ether way! And I could always be wrong, just another senior moment.

 

the internet says there 64cc, doesn't matter to me what they are lol, got bored so i drilled the steam holes while im waiting to get the block back from the machine shop.

 

and another source says 67 cc

 

Never worry about 1cc especially on stock stuff, they just aren't that accurate (unfortunately), like I've said elsewhere run a straight edge along the rocker studs or the edge of the valve stems, you think there all straight- aint so.

 

Doesn't matter how inaccurate "aren't that accurate" is meant to be; most stock stuff, from the 70s most of all, doesn't even make it that far.

Pour em and measure em, and then they just are what they are, no matter what drivel about "specs" is posted on the Internet. If they're REALLY just WAY off, like more than 3cc or so, then it's time to figure out what to do. But with what you're doing, they're probably fine. I'd say if they're within 2cc they're close "enough" for most street uses, and within 1.5cc they're better than most.

Then, think about it... if they were a little different, what would you do about it, anyway? There comes a time when it all turns into just a bunch of armchair beer talk.

I'd be willing to bet that there's more difference in the deck clearance from cyl to cyl than that. Stock stuff is that way... once you get one error cleaned up to the point that it is swamped by the next one, there's ALWAYS a "next one". You're just playing the game of "measure with micrometer, mark with chalk line, cut with chain saw" anyway. There's SO MANY ways stock stuff is "off", you wouldn't believe it until you actually try to get it all RIGHT. It's scary sometimes that some motors even RUN at all.

 

got my camand lifters today, and my block back from the machine shop threw my heads on top just to tease myself... takes a-lot to get me excited but im there!