#1  
Old 04-20-2022, 11:58 PM
gavin gavin is offline
Senior Chief
 
Join Date: Apr 2011
Location: brisbane australia
Posts: 296
Default 1960 heads.

First of all before I get told there are better heads this what the guy wants to use. I am presently trying to modify a pair of 1960 heads. I have sourced new valves at standard size. These are about 5.25” so I could not adapt sbc valves of a bigger size. I was looking at using crowder 26906 sbc springs but these have a 1.8” height and I’m not sure if the deck is thick enough to go the extra .260” depth. Any suggestions on a better spring? We want to use a cam with some lift. Second I want to use spotts rocker stud kit so has anyone used them on 60 or earlier heads? And third rocker arms . Do the 61-66 rockers work on these heads? Many conflicting opinions so who has actually done it? I am going to port them a little the intake is not that bad just under 64 ho heads. Exhaust is horrible. Any and all advice taken on board. I will post my results when finished so the next poor sod knows what’s needed. Thanks.

  #2  
Old 04-21-2022, 01:24 AM
Jack Gifford's Avatar
Jack Gifford Jack Gifford is offline
formerly 'Pontiac Jack'
 
Join Date: Dec 2004
Location: Phelps, NY 14532
Posts: 10,176
Default

I believe '55-60 rocker arms are identical- and quite different from '61 & later. They are almost identical to SBC rocker arms. So there aren't many good options for rocker arms. On the '58 in my GMC I was able to use SBC aftermarket needle bearing roller tip rockers, but it wasn't easy. Since I was opening the stud holes from 3/8" to 1/2" I had the freedom to offset and angle the studs enough to get the geometry right. But the valve stem lengths and pushrod lengths also had to be custom.
I've been quite happy with getting rid of the bathtub chambers of the early heads (as Mickey Thompson did with Pontiacs back in the early sixties). In my GMC's '58 I used pistons with a D-shaped dish to give 9.05:1 C.R. This left a nice squish area in the unmachined portion of the chambers. It runs great.
Attached Thumbnails
Click image for larger version

Name:	58_head0001.jpg
Views:	70
Size:	107.0 KB
ID:	589055   Click image for larger version

Name:	58_chamber0001.jpg
Views:	68
Size:	110.0 KB
ID:	589056  

__________________
Anybody else on this planet campaign a M/T hemi Pontiac for eleven seasons?
... or has built a record breaking DOHC hemi four cylinder Pontiac?
... or has driven a couple laps of Nuerburgring with Tri-Power Pontiac power?(back in 1967)
  #3  
Old 04-21-2022, 06:39 PM
gavin gavin is offline
Senior Chief
 
Join Date: Apr 2011
Location: brisbane australia
Posts: 296
Default

Thank you for the information. Was the angle changed much and how much was needed? Did it mimic the stock centres and angle of the chev head? I have spare heads to practice on and a mill. And do you remember what spring was used? All information very appreciated.

  #4  
Old 04-22-2022, 02:56 AM
Jack Gifford's Avatar
Jack Gifford Jack Gifford is offline
formerly 'Pontiac Jack'
 
Join Date: Dec 2004
Location: Phelps, NY 14532
Posts: 10,176
Default

The stud angles didn't need to change much. I did not start with any SBC knowledge or layout drawings. I just worked with the SBC roller rockers and the Pontiac stuff until I got the rockers' roller axle centers to move parallel to the valve stems at mid lift, and roller contact traversing the center of the valve tip. I may have needed to elongate the pushrod guide holes- can't remember. I'm at fault for not documenting everything. I could look at my notes and possibly find valve lengths, spring heights, etc.- but don't hold your breath.

__________________
Anybody else on this planet campaign a M/T hemi Pontiac for eleven seasons?
... or has built a record breaking DOHC hemi four cylinder Pontiac?
... or has driven a couple laps of Nuerburgring with Tri-Power Pontiac power?(back in 1967)
  #5  
Old 04-22-2022, 06:10 AM
gavin gavin is offline
Senior Chief
 
Join Date: Apr 2011
Location: brisbane australia
Posts: 296
Default

Thanks for the info at least I have a starting point.

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 02:09 AM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017