[mstan]

I posted this question in my other thread but it doesn't look like anyone saw it. Are the #11 heads off of my 1970 350 engine usable on a 400 or 455? Or are they junk?

Thank you.

[mstan]

I posted this question in my other thread but it doesn't look like anyone saw it. Are the #11 heads off of my 1970 350 engine usable on a 400 or 455? Or are they junk?

Thank you.

[cpetrice]

on a 350 these heads produce 8.8 cr. more on a 400,even more on a 455. The only problem is the small valve size,1.94 and 1.66,the 455 would not breath well. I would put them on a 400 before I put them on a455,but the cr on the 455 would be sweet!

[Bud Lyons]

In 1970 the lo-po 455's came thru with #11 heads. draw backs are small valves and pressed in studs. You can have a machine shop install bigger valves and tap the heads for screw in studs. IMOHO, I would look for a set of heads that had the big valves and screw studs already. Their's plenty out of them there.

['ol Pinion head]

'70 Low perf 455's recieved "15"s (87cc)
'70 Low perf 400-4bbl- "16"s (80cc)
'70 35O (all were 2bbl)-"11"s (prob 75cc, need to ck 'em)

All these heads were small valve press-in stud. Before one starts sinking a ton of money in a set of these, they need to look at their ultimate performance goal. Personally like the versatility of the chamber sizes on these heads. Only problem I've run across is my local Pontiac headporter buddy could not max port a set of '70 #15's, he hit several water jackets. Would love to hear other's heavy porting experience on these.

[Will]

OPH,

What I've heard about the small valve heads is that with bigger valves and some port work it's not too hard to achieve a 240-250 cfm port without hitting. Of course, that's not "max ported" but it is plenty for a hot street engine. If I had the time, I'd port up the #11s I have laying around.