If you don't find the VIN there, you're pretty much out of luck. If you're determined to find proof, you might consult with a Corvette restoration specialist in an attempt to find someone that can "raise" the numbers that had been machined off, using acid or infrared scanning or some such means of utilizing forensic science for auto restoration.
Seal In The FreshnessI have an '87 Buick Turbo T engine that I rebuilt over the winter. I had it bored 0.030-inch over and had it O-ringed. I'm having a problem with antifreeze going somewhere, and it's not going on the ground. I used SCE copper head gaskets and sealed the water jackets with Permatex Hylomar high-perf gasket dressing and flange sealant. I was wondering if you could tell me how I can seal the head gasket better when I tear it down again.Charles Good Muncie, Indiana
The combination of SCE copper head gaskets and Hylomar sealant with O-ringed blocks is a common approach to sealing the cylinders of high-boost Buick turbo V-6s, but this method can be somewhat unforgiving. The copper head gaskets don't have the ability to conform to imperfections in the sealing surfaces like conventional composite gaskets do, which necessitates the use of gasket dressing. Unfortunately, that still doesn't guarantee successful sealing.
Before you tear into the engine, try retorquing the heads again. You should be using the torque sequence prescribed in the Buick factory manual and the torque specs for the bolts you're using-for example, aftermarket performance fasteners, such as ARP, often have higher torque specifications than factory fasteners. Also verify that the specs you're using are intended for bolts with lubed threads and shoulders-dry bolts will give higher torque readings with less stretch due to the increased friction. There's a chance that you'll get lucky; re-torquing the heads may do the trick if they simply weren't tightened enough previously, or if they were never retorqued.
Another potential source of your problem that should be checked prior to teardown is the factory oil cooler. Assuming that your Buick still has this unit, pressure-test the cooling system to see if this is the source of your coolant loss. The original oil coolers on Turbo Regals were notorious for developing internal leaks as they aged. If this were the case, you'd probably be experiencing the dreaded crankcase milk shake effect-a creamy, gooey mess that results from the mixture of oil and coolant, which would be evident when looking into the oil filler, or possibly even on the dipstick. If you can't get a clear view inside the crankcase, pull a valve cover and have a look.
If and when you do have to pull the heads to reseal, check the heads and the block decks for trueness, preferably with a machinist's straightedge. Once that's been verified, clean the sealing surfaces thoroughly with a good solvent, making sure to wipe all the solvent residue from the surfaces once they're completely free of any sealant, oil, antifreeze, and so on. Then, begin the process of installing the new copper head gaskets using the Hylomar, following the instructions to the letter. Once the heads are in place, torque the bolts, again following the factory sequence and stepping and using the final torque spec that corresponds with the bolts being used. Once the heads are installed and torqued, don't start the engine. Instead, let it sit, at least overnight, and then go back and retorque the bolts the following day. This time, go around the heads and loosen and retorque each head bolt one at a time using the normal sequence. After the engine has been run for a few days and has reached normal operating temp a few times, repeat the retorquing procedure one more time. Hopefully this will ensure a positive seal.