I have seen many posts and threads like this over many years and just want to "vent" my opinion concerning short block assembly on a performance build, especially in reference to a turo Buick V-6.
For more years than most of you have been alive, I have been working on cars and engines!
Before I rebuilt my first Buick V-6, I did a LOT of research seeking info and talking with performance engine shops. After discussing tolerances, clearances, various specs, which parts to use, machining operations, assembly procedures, special tools required and the all important workmanshp warranty, I came to the conclusion it would be much smarter to pay an expert to assemble my short block.
This has proven to have paid off after 600+ turbo Buick V-6 builds that have we have shipped all over the country and Canada.
My thought is someone that assembles performance engines on a daily basis, and has the proper knowledge, experience and tools is much more qualified than myself. Having worked hand-in-hand with many Buick engine assembly processes, I have seen many little items I would not have corrected, or even found. With feedback, we have incorporated many changes and improvements for performane and reliability.
I cannot afford to ship an engine 3000 miles and have an issue due to assembly or a stupid mistake, and our record is 100% successful at this point.
This is NOT directed at anyone specific, but just pointing out spending $2-300 for a short block assembly on an expensive rebuild may certainly be worth it in the long run.