LA360 compression

ok engine builders. Here is my dilemma. I bought a Mabbco rebuilt 360 short block from a member. Some upgraded stuff like KB high compression flat top pistons, moly rings, 272 muscle cam (272/272 duration 454-454 lift) Cloyes HD timing chain and sprokets. .30 over bore. Got a nice brand new set of Speedmaster aluminum heads with 68cc combustion chambers.
Here's the problem; my engine is at a builders for finishing. Went by there yesterday and he said this engine will be an absolute dog as it sits now. He doubts it will make 8:1 compression. Yes, the pistons are below deck a little, but he says I am losing a lot of quench with them. He suggests new pistons, rods, roller cam and new crank. That's an expensive prospect, considering what I already have in the motor. Also, this guy is a very well known builder with a great reputation and is well known in the racing circuit. His shop is incredible and he rebuilds engines for a living, and has many many great reviews. He does not even want to assemble the rest because he says he knows I will be disappointed.
What to do? Will this motor be a dog like he says? I don't know that I have the scratch to have him tear down this motor and upgrade it to a stroker.
TIA.
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I used the NGK compression calculator and with kb107 pistons 0.012" below the deck and 68cc heads,0.039" thick headgasket with pistons having 5cc valve reliefs and a 4.030" bore stock stroke, I got a compression ratio of 9.90:1. I don't know how your machine shop came up with 8.0:1