Ok, so Ted already answered my general question about valve size and such via email when I signed up...

but...
For a 292,
I am still trying to find a head to use. I'd like to use stock. Initially I had some ported ECZ-G heads, but my machine shop didn't like the valve seats, or how much they'd been milled.
I had access to some 471 heads, but I really don't want to go backward with the compression ratio. Rather stay as close to 9-9.5 as I can. (maybe that's unnecessary) 
I got some other ECZ-G heads that were "nicer" but there are cracks in them, can be fixed, but my machinist thinks it'd be a poor choice for my build.
NOW
I have a set of ECL-C heads that don't look to have ever been milled. The valves are smaller of course, and Ted has mentioned that it's not really beneficial for street use to have larger valves...
BUT
I still want them.
Machine shop found another set of ECZ-G but it's $400 just for the bare heads... my ECL's are free basically.
I have the stock heads off the engine C1TE flavor.
Question: Do I let the child in me win, and have the shop grind out the valves to the larger size, or just have them build these ECL's stock and be happy? ... OR use the stockers (C1TE)?

ECL's 1.78 intake now, C1TE have 1.64 intake, ECZ-G have 1.92

Follow up question... are the ports different on stock heads between the different applications?

Thanks!

If it were me, I would install 1.940-1.960" intake valves and 1.550" exhaust valves.  That would give you more seat area to work with, and not be so large so as to create a flow restriction.  You can actually go to 2.020/1.600 size valves, but that shrouds the combustion chamber walls a bit, and moves the valves closer to the cylinder walls.  Don't be afraid to use cut down valves if you can't buy the size you need at the current time.  SBC valves +.200" will work, or you might even get by with SBC +.100" valves if your camshaft is mild.  I have ported dozens of the -G heads, 113's, 471's, and most of them get oversize valves for better air flow.  Joe-JDC

JDC

I have a set of Mummert pocket ported G heads in the classifieds.
I’m going to modify the add to include valve covers, head gaskets, intake and exhaust gaskets, valve cover gaskets, all Best Gasket.
I also opened up the ports a little.  

What city are you in? I have a lot of heads, I'm in southern CA.

Did you check out the article on Timmy's Y-block Page?

Thanks for all the replies... I don't know about Timmy's, I'll go spelunking...

I'm in Napa, CA.. trying to keep the cost down as much as possible, so I imagine the Mummert heads are out of my range.

Sounds like I'll probably go with having the shop grind it out, cost depending. They're gonna get me a comparative estimate to consider. I sure wish my ECZ-G's woulda worked as I had wanted the compression ratio closer to 9:1. I think I'm going to be around 8.7:1.

My 292 ended up .040 over, with the stock stroke of 3.30 and estimating the remainder of the measurements... and 73cc for the heads, that's how I came up with 8.7

I get 8.34:1, assuming 0 deck height and 10cc for the head gaskets.  Gs would put it up around 8.7.
It's hard to get above 9:1 with a 292, without domed pistons, more displacement (than a typical overbore will provide) or the aluminum heads.



Lawrenceville, GA

A mild cam/w low duration and no overlap will help the dynamic compression ratio. 

Mummert advertises 1.84" intakes for the small valve heads or possibly as a replacement for 1.78" intakes.. I believe our man Ted recommends if redoing an engine, for reliabilty, to replace the exhaust valves & then you can decide on size..   


Paul

yblockguy.com/techtips/cylinder_head_mods.html