If you're going to use a machine shop that's local to you and put it together yourself, "maybe." There's a shop in Niles, Ohio that the Father was a Guru with the 394/371/324/303 early Oldsmobile engines. He even has aluminium heads for them, large lifters, etc. He built the engines complete and dyno'd them. I "use" to hear good things about the "Father." Remember I said "use" to, 20 years ago. Now, I had never actually met or talked to anyone that actually had an engine built. Maybe he was good, maybe now. Now, I've heard stories about the Son, all I can say is "no comment." I will say if you have "years" till you need the engine and love writing checks, with missed deadlines, no final documentation, well, "no comment." In my search for parts, I was in Pa, over passed Dubois Pa. The guy had some 1967 Cutlass/442 parts. He had a 1967 442 tore apart. The 400 E block uses the 0.921" "big" lifters as does the 394. We're BS'ing and he says, "did you ever hear of "Xxss Racing Engines" in Niles, Ohio. I says, yep, 6 miles from me. He has the engine sitting in a crate. He says the engine made 340hp. And he has (please, sit down) $14,000 in the build. I said, those engines supposedly made 350 hp from the factory. His story took a while for him to tell me, all I can say is, "no comment." So, keep sitting down, since then, two people told me about similar 394 builds, both people told me their aluminium headed 394's "BOTH" dyno''d, (drum roll) 340 hp. ZERO of them had the Dyno chart. Supposedly, it's an Ancient Chinese Secret. So, all I can say is, NO COMMENT."
I will make one comment, Good luck.
Yes, RXxS Racing's reputation is in the toilet. I've met the Father 20+ years ago. He's a Guru with the older "Rocket" engines. He was a "little" arrogant, kind of like being a little pregnant. He has a very nice 1950 Olds coupe, 3 on the tree, two 2 barrel carbs. I casually mentioned, my Dad use to have a 1950 Sedanette (fast back) and I like that style. I think he got offended because I said that, whatever. I had a good running 394 I was selling and he tried "really low balling" me. I sold it on ebay and got triple his offer. If one just needs some parts then you can try using him but only buy one part at a time. Jmo.