Spinning the Wheel of 455 Mystery

Any guesses as to what piston this is? Either stock or a stock replacement for sure, but which one remains to be seen. I forgot my caliper, but I think they're definitely a solid .040 in the hole. Not like a zero deck situation at all, although I didn't expect that. Will measure bores and deck clearance tomorrow probably.

 

Those are the stock 75-76 pistons.

 

What kind of compression would I be looking at with a set of 1970 heads and the .027 cometic gasket?

 

Not a lot.
But totally streetable for fun.
Piston is down the hole.
You can measure w a straight edge and feeler gauge to get it close. Straight edge across deck left to right n measure at side when pivots on pin

 

In 1975, Buick engines were a metallic, aqua blue.
But in the grand scheme of things engine color doesn't mean a thing as far as the year

 

It's probably an issue that needs addressed then. Hoping to take my ~3400 lb car into low 13's at least, so I'm going to have to find some compression to support a more than stock cam. I do have headers for it.

 

After checking and measuring, we have a Winner! Two different types of piston in the same engine! Pistons with 2 marks (6 of them) sit around .085" in the hole on average. Pistons with one mark (only on cyl. 5&6) are sitting just .045" in the hole. Bores measure 4.312 at the tops with my cheap calipers. Should they check round with my micrometer and snaps is it okay to order new standard bore forgings, and have the rotating assembly balanced with them?

Also, lobe lift with stock rockers shows up around .472/.475 lift, so I'm going to go ahead and guess it's over cammed for having 7.8:1 on 6 cylinders and 8.2:1 on 2. Somtimes people just do it right

 

Made a little more progress on the 455 this morning. How can I identify this cam? The casting number is 1231304, and it has 990100 etched into the back of the cam. I measure 1.44 and 1.45 lobes, for about .290/.300 lobe lift. It has blue paint around the front of it where I understand grooves are present on stage 1 & 2 cams, but no grooves. It is basically new, so if it's something aftermarket that would work alright I wouldn't mind re-using it. I have all lifters in order.

 

The 455 is now completely dismantled. Seems crank was turned .010", but of course they didn't change rod bolts, why would they . The condition of the bearings does not impress me for being so low-mile, although the silicone blocking part of the oil pickup from the block to the pump gives me thoughts as to how they wore that way. I'm sure the engine wasn't assembled as cleanly as it should have been anyways. I think the crank will be fine, if not just with a polish. My guess is it was sent out to be machined and nothing was balanced when this was put together either. Oh well, I press on.

 

Not much but a little update, first bit of parts coming in for the 455. I was tossed between these and TA 1607's for their .010 taller pin height, but I found these for cheaper than they seem to be going for, so decided to go ahead with the piece of mind of forged. I noted they all seem to be marked by weight, and all at 654 grams, does that seem right? I will get a scale and check myself, but about 100 grams lighter than a stock cast piston is no joke.

 

Parts are in and should be off for machine shop next week sometime. The cam in this engine degrees out to what looks like a Sealed Power CS1165R, what are opinions on this cam? I can't find much of anything on people who are using it, and certainly nothing on YouTube about it. I was originally looking at the TA 284-88h, which has a touch more duration.