[mgarblik]

It's been a while but another little update on the re- re build of this SD-455 engine. The short block is now complete and I disassembled one head today to take a look. Everything is pretty dry in there but only a tiny bit of rust here and there. The heads are not ported or gasket matched. It has had a valve job and bronze guide liners installed and honed to fit. The guides are perfect. The original valves were reused and guides may have been cut for PC seals. Since I have never worked on a set, I don't know how they came from the factory. My plan is to lap the valves to get a visual look at the valve job, test the springs, upgrade to viton valve seals, clean and put them back together. The keepers were reused and in marginal condition. They will be replaced. Overall happy they don't look all hacked up inside. In the pics you will notice these heads have NO casting codes on the exhaust ports. Also no stampings on them anywhere. I looked carefully. No date code or day night shift. Only the part number, that's all. The connecting rods were "A" series forgings and I was told heads without any numbers were early castings?

[mgarblik]

Few more pics. Sorry some of these pictures are sideways. Don't know why it does this or how to turn them.

[Gary H]

Originally Posted by mgarblik

Few more pics. Sorry some of these pictures are sideways. Don't know why it does this or how to turn them.

My heads are cast the same as your, no "16" on the exhaust ports, but has the full part number on ridge below the valve cover edge. My intake was actually cast in November of 72'. The car was built the 2nd week of June. Brewster Green with Beige cloth interior. Sold here at Coggin Pontiac in Jacksonville.

[Gary H]

Originally Posted by Gary H

My heads are cast the same as your, no "16" on the exhaust ports, but has the full part number on ridge below the valve cover edge. My intake was actually cast in November of 72'. The car was built the 2nd week of June. Brewster Green with Beige cloth interior. Sold here at Coggin Pontiac in Jacksonville.

Couple of pictures of the head code and trim tag

[mgarblik]

Originally Posted by Gary H

Couple of pictures of the head code and trim tag

Those cars might have been on the line together. That would have been a great color picture. Your heads look the same as mine. BTW, I looked very closely between the seal groove and lock groove on the valves and did make out what looked like possibly a number or two on a couple of the intakes. Nothing on the exhaust. That was with my camera and a 10X magnifier glass. So no good on part numbers. 99% sure they are the original valves. They do not have enough margin to be new valves. They are certainly usable IMO.

[Dragncar]

Originally Posted by mgarblik

It's been a while but another little update on the re- re build of this SD-455 engine. The short block is now complete and I disassembled one head today to take a look. Everything is pretty dry in there but only a tiny bit of rust here and there. The heads are not ported or gasket matched. It has had a valve job and bronze guide liners installed and honed to fit. The guides are perfect. The original valves were reused and guides may have been cut for PC seals. Since I have never worked on a set, I don't know how they came from the factory. My plan is to lap the valves to get a visual look at the valve job, test the springs, upgrade to viton valve seals, clean and put them back together. The keepers were reused and in marginal condition. They will be replaced. Overall happy they don't look all hacked up inside. In the pics you will notice these heads have NO casting codes on the exhaust ports. Also no stampings on them anywhere. I looked carefully. No date code or day night shift. Only the part number, that's all. The connecting rods were "A" series forgings and I was told heads without any numbers were early castings?

Pontiacs have beautiful chambers when you compare them to Chevy chambers of that era. All the machined cuts, nice.
Every time I look at them I always think of the 90cc head prototype that was made.
Its amazing PMD got that low CR engine to run so well. 10-1 would have ruled the streets.