Gain extra benefits by becoming a Supporting Member Click here find out how!

Classic Performance Products Nu-Relics Power Windows
American Auto Wire Hellwig Products IncPerformance Rod & Custom
Danchuk Catalog

Username Post: '78 Chevy 350 > Heads        (Topic#347320)
Forum Newbie
Posts: 1

Reg: 09-25-17
09-25-17 01:39 AM - Post#2708743    

So I've got a 350 here in a '78. The block seems solid after replacing gaskets. Held good compression though I can't recall the numbers. Runs fine, feels plenty torque happy for my needs. However I have these heads laying around and I'm wondering if they would be considered an improvement. From my research they look compatible but I haven't actually made sure they bolt up yet. Fresh pushrods and rollers were installed.

From what I can tell it's been ported (from the roughness I'd guess not actually polished up but feels smooth), 2" intake port, and looks Machined. Note that they do have metal shavings and junk all in them from sitting under my workbench for so long. Also looks like it has a new spring setup (duals?). I'm far more familiar with modern engines but am capable of replacing of fixing anything that breaks.

I'd appreciate a direction with these heads, love to know if it'd be a solid flow improvement, if it's even totally compatible after cleaning up or if not what the value might be on them. Thanks guys!


Valued Contributor
Posts: 4085
Loc: Sweden
Reg: 08-23-07
09-30-17 10:59 AM - Post#2709301    
    In response to Mydailyistrash

Good classic camel humps. Not sure if they have accessorie bolt holes? If i'm Reading the date stam pkorrect the head shown is from november 71. That should mean accessorie bolt holes, since the long pump came in 69 in cars. Pickups and Corvettes still had short pumps I think.

That would be relevant to me at least. I guess you want to keep everything else (water pump, pulleys and brackets).

The "64cc" would mean just under 10:1 compression with a standard block (Ø4" , not decked, .040" gasket).

Those valves could be 2.02/1.6 which is really good. 1.94/1.5 would be still fine.

Screwed in rocker arm bolts is great!

The springs are single. The flat sping inside is a harmonic damper spring.

The valve seals look new.

I would try them on. mp;fea...

Deceased Member RIP
Posts: 5917
Age: 70
Loc: Everett, Wa.
Reg: 02-26-08
10-19-17 10:23 PM - Post#2711446    
    In response to Impala65SS

186 are a 70cc combustion chamber head; slightly smaller that what you have at 76cc chambers. They were the LT-1 heads for 1971. But, you are also stepping up to 1.94 intake valves, some port/chamber work, screw-in studs, and better springs it sounds like. An overall improvement. If you have dished pistons, you may want to find similar, but 64cc chambered heads, and add a mild cam and lifters. I am Butch/56sedandelivery.


Icon Legend Permissions Topic Options
Report Post

Quote Post

Quick Reply

Print Topic

Email Topic

FusionBB™ Version 2.1
©2003-2006 InteractivePHP, Inc.
Execution time: 0.173 seconds.   Total Queries: 16   Zlib Compression is on.
All times are (GMT -0800) Pacific. Current time is 03:37 PM