[Adger Smith]

Sounds good to me. The caps tie the bottom end together and help hold the long stroke crank. The block fill makes the weaker cylinder walls stronger. A shop that puts on caps and block fills will usually be doing the other thing that is a common problem with a 400 block. Blocks bored and honed "Without" stress plates are prone to cylinder wall distortion and bad ring seal. There can also be cracking out of bolt holes if plates aren't used. I think that is the most common complaint of the 400's when they were first being used as race engines. A shop that takes the time to do the right things to a 400 block will probably be using plates. Run a leak down on the engine before you buy it and see if it is healthy. don't treat it like a 302 SBC and try to make it an RPM king. They are Torque engines. Gear and converter it and keep the RPM well below 7,000 and it will make you a strong bracket engine that should last a season or two before freshening. I've done quite a few of them over the years and am doing one for myself at this time. I plan on putting it in a former Comp Street Roadster I have to run some local Index classes. Another issue with big SBC's (until lately) has been heads. You can never put too big a head on one. That is why you shouldn't try to RPM it. I've got one customer that uses one in a S/G style Monza that has Track 1 heads 11-1 compression and (FT) Eagle rotating assy , Small comp solid roller. (264/272) 830 carb. He runs foot brake/NoE as well as some 6.50/7.00 index classes and is deadly consistant with it. He is seen quite often in the last couple of rounds and at the winners circle.
You would be surprised at how tight his PTC converter is.
I don't think twice about using a well prepaired stock 400 block for a good mild bracket application.