I actually never sea trialed the 340 with 5.7/ B3's.. I was going to and depending on performance make an offer, literally the next day he sold it before I spoke with him. From what the guy was saying, the performance was similar to 7.4's and I would tend to agree. The engines are roughly 400...
Yes there is a ton of room to work and at least things that I can commonly do myself, I will still be able to. With the 7.4 there is ZERO room for anything.