I'd build it yourself. Have them hot tank the block, deck it the necessary amount to square up the deck surfaces (varies from engine to engine), and install TA's grooved cam bearings with the oiling holes at 7 and 3 o clock respectively. After that, if you have even a basic 200pc socket set, and a torque wrench that goes to at least 200ftlbs, you can build an engine. If it's a time/space limiting factor, just ask around. People screw up buicks because they build them like chevies. Chevy pattern cam, big bearing clearances, and high volume pumps. All no no's in the Buick world. You could have them assemble the short block, and bolt things like the heads, intake, and accessories on yourself. .002 MAX on bearing clearances on the rods and mains and you'll be good.
If you know what you want and have the information you need. Tell them how you want things done. Cheap piston sets make low compression. Be ready with knowledge and the shop should do a decent job. Ask here if you have questions. Piston and cam choices. Any other information.
FYI I was looking up the crank journal specs in my 1973 Buick manual and it lists main clearance to be .0004 - .0015". My machinist looked it up in a book they use and it showed .0007-.002"
Use the GM specs. I personally think the original GM bearings are thicker, & have full groove, compared to TRW, and other service brands. Too bad you can't buy them. Tight .0004 - .0007 is impossible to achieve just dropping in an original to spec, stock unground crank using aftermarket bearings without grinding caps and align hone. I have never checked King bearings though.
.001 to .0015 is perfect for bearing clearance. Under that would be almost impossible. Definitely under .002 if you want decent oil pressure.
Don't hesitate to ask here if you have a question, but do search around the forum a little first. No dumb questions. Try to keep it to this thread as well, a lot of threads can be confusing.
I had mine rebuilt at Portland Engine Rebuilders around 2009, But they've since relocated to Aurora. They did all my machine work exactly to my spec, understood the difference between Buick and Chevy tolerances, and didn't look at my build like I dropped from space. They didn't use the TA cam bearings I bought, so I had to swap them out, but good machine work, and had no beef with me doing the assembly myself. I'd recommend them.
