Spotted a 1973 Pontiac 400CI in the local Craigslist last weekend. The picture showed the engine disassembled, in parts, and a surface rust block. $350 cash. I have been looking for a back-up block/iron heads for my '68 Lemans just in case the 455CI (.060" over) lets go OR I keep it so long I wear it out and need another engine. Most in my area are high dollar as junkyards and old parts get harder to find as Charlotte & the surrounding area expand, modernize, add more zoning regulations, and push old community out. They just crushed the last yard about 3 miles away from me that had a few oldies, one being a 1968 Catalina 4-Dr with 400CI that was so far in the woods that it had trees growing around and through it that the old junk yard owner could not get to it. Still had green anti-freeze in the radiator. The old owner either retired or passed away - just a big empty lot now.
Emailed the seller when I saw the ad and he told me it was mine but it would have to be this weekend when he could meet, so we met this morning. Another "old school hot rodder" like myself 2 years younger with a couple old rides. His son bought a 1966 Tempest 10 years ago that this engine came out of which they are rebuilding (upgrading) together and the son is installing an LS3 - with dad trying to convince him that it was a Pontiac and should be kept as such. But, he understood it was his son's build, different generation, and they no longer needed the 1973 engine with the decision to go LS3.
I got what looks like an untouched block that had been set outside and has light surface rust, but nothing heavy. Rest of the parts were kept in the Tempest trunk. The block is a 1973, code X5, 230 HP 4-Bbl/automatic engine, dated D143 with the big valve 4X 7H heads with screw-in studs dated D143 & D163 which couldn't be any closer to each other, so everything matches. Most parts are there, but some small bolts and other fasteners are missing which is not big deal. Mainly wanted the block & heads, and all the typical bolt on parts. Has the 5 motor mount holes on the side of the block and the screw hole on the side of the block for a clutch ball used for manual transmissions.
Tucking the engine away in my shed, I noticed the impressions from the intake gaskets on the intake revealed that the intake ports were tiny (1 3/4"H x 1 1/16"W vs the head's 2 1/16"H x 1 1/8"W). It was a 2 Bbl intake with a later Rochester carb. The date code was L185. Thinking the 4bbl/Q-jet was pulled and replaced, it might have be a 1975 intake. I looked up the casting number and it turns out it is a 1966 2Bbl intake. It also has the stud drilled for the vacuum supply as one of the carb hold down bolts which is typical of the early intakes. I can bet the engine was real responsive with the smaller ports and high velocity of the fuel mixture, but didn't RPM very high as power dropped off.
The crank was drilled for a pilot bearing for manual transmission (it is said not all cranks were drilled, but don't know when this stopped). Looking at the crank bearings, some showed light-to-no wear going into the copper with one into the copper. The bearings in the rods, the lower shell halves were all good, but most all of the top shells were worn through to the copper - which is where you get into the infamous rod problems with Pontiacs and where the rod is typically cited as the fault, not the "other" causes which created the rod failure. It may have had high miles, been beat on, poor maintenance, or a combination of it all. The pistons looked good with very minimal scratching on the skirts. Bores looked good with just slight ridges, I'll find out from my machinist the bore size and have him hot tank/magnaflux it for cracks.
So I think I scored on this one unless magnafluxing proves otherwise.