Hi everyone I recently picked up a 1970 455 motor that was rebuilt but never made it back into the guys truck, then sat in a shop for 25 years. I know it definitely needs another rebuild now. He told me he bought a stage 1 cam from GM and put it in during the build (haven't got it apart to confim) I've come across some irregularities with some of the parts numbers and figured that there were a few "donor" parts from other engines used (some 430 parts) the heads numbers have me confused one chart I referenced said they were 67-79 400/430/455 heads and the other chart said 68 400/430 heads?? I'll list all the parts and their numbers. -Right head:1382091 B/20 with 56281 stamped on the front -Left head:1382091 D/15 with 47281 stamped on the front -Block: 455 GM2 1231738 Between 1&3 pistons #6 stamped Between 5&7 pistons SR 375 Front left of block 555 55844 22 -Top right of water pump flange D9 -Distributor:1111335 9A 15 -Intake manifold:B13860032 H26 -Qjet: 7033240 LA 2292 -Left EX manifold:B-1383549-H A22 -Right EX manifold:B-1383648-A A22 I've pretty much narrowed down all the dates/codes except the heads and the charts are confusing me. Was it common for GM to take leftover parts from the previous year and other motors like the 430 and use them up on the early next year model engines?? Any help would be great! Also on the top of the pistons there is 30 stamped in them does that mean they're. 030" replacements and the block was bored or did the stock pistons have that?
The block came from a Non stage 1, 70 GS 455. From an imperfect memory the intake manifold is from a 71 455.
Here are a couple of the charts I've used to reference the numbers they look the same but the information on them is slightly different.
If your going to rebuild it then start with a clean slate and the correct info to make parts chooses! You have the heads off so if the valves sizes are the same and the chambers are the same then your good in that department! The next thing I would do is confirm that the block, heads & Crank pass a Mag test, only after that start dreaming and thumbing thru catalog's!
That's my plan, tear it down get it all checked out and go from there. I was just checking into some of the parts to see what I bought. If everything checks out I plan on doing some gasket/port matching and some port polish work to the heads myself. I know TA aluminum heads are the best way to go but I won't have $3-4K to spend on them. I may reuse the stage 1 cam (If it's really in there) or go with a TA cam. I noticed some very light surface rust in the cylinders could that be cleaned up with a hone job or am I looking at boring the block? It's at .030 over now judging by the pistons that are in it are stamped 30 on the tops of them.