View Single Post
  #7  
Old 03-12-2026, 01:29 AM
Jack Gifford's Avatar
Jack Gifford Jack Gifford is offline
formerly 'Pontiac Jack'
 
Join Date: Dec 2004
Location: Phelps, NY 14532
Posts: 10,340
Default

For the Tri-Power ('61 SD) in my GMC, I built a variable spring seat for the power valve which is externally adjustable. The range of settings is about 5-13 In.Hg. I set it at 8 in.Hg. and haven't changed it in the 10,000 miles I've put on it.
Attached Thumbnails
Click image for larger version

Name:	power_valve0001.jpg
Views:	47
Size:	203.9 KB
ID:	666140   Click image for larger version

Name:	power_valve_ext0001.jpg
Views:	48
Size:	68.8 KB
ID:	666141  

__________________
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)
... or has a Pontiac born the same year as Jim Wangers? (1926}
The Following User Says Thank You to Jack Gifford For This Useful Post: