Did he have a 598? This is were I bought my engine.

Still has it, Quadrotor 598

Well, mine are 4.5 bores with 4.375 cranks. 8:1CR with 6 psi....200 hours and counting. Way better than GM blocks.

The Dart block is an excellent piece. It's about 75 lbs heavier than a 502 block, so that should give you an idea of how much more material is there.
Personally, I prefer the Merlin blocks. I like the billet main caps on the Merlin better than the steel caps on the Dart. The billet main caps on a Merlin block are some really impressive pieces. Previously, Dart only offered a ductile iron or steel cap. I think they may have added a billet cap, but as I said, I don't use them. Just my preference.
If you are building a supercharged 598, then go with a 6.635 rod and 1.27" comp height piston. No one makes a 1.25 piston in an inverted dome in order to use a 6.700 rod.
Give me a shout if I can help in any way. Good luck.
Eddie

I'm run a dart big m, beefy block, MUCH better than the Merlin 2 I used to run. The merlin 2 had some deficiencies , no extra hold downs in the center valley (I was making 950 hp and when I tore the merlin down to freshen the motor the head gaskets were on the very verge of blowing) , the fire rings were barely in place and starting to come apart. Make sure the heads you buy have the extra holdown holes for the center holdowns . I also ran into a problem with the hydraulic roller lifters coming into the chamfer and bleeding oil pressure at idle and below 1000 rpm's, the lifter bore bosses were taller on the dart. Remember that ALL these aftermarket blocks need just about EVERYTHING re-machined as they come pretty tight from the manufacturer and are nowhere close to being ready to run, you can easily spend 500-1000$ having everything made perfect! I also drilled a extra oil bleed on the front of the dart block to spray oil onto the timing chain thrust bearings. I used the fancy melling blueprinted pump and my oil pressure is still almost 100 psi cold even with clearences over .003 on the crank so do some research into what oil pump you use, if I was doing it again I would probably go one step back on the oil pump as that is too high. When I had my block prepped I had my machinist normalize the block by heat cycling it for 7 days before doing any machine work as the block is "green". I made over 1100 hp (540 cu inches) and have had no issues, overall I am real happy with the block. I'm not a fan of 4.600 bores so I kept mine at 4.500 to keep the cylinders as stable as possible, Smitty

Is it fuel injected or carb?

GPM I just confirmed with Gordon at Paul Pfaf that it is a 4.6 bore.

GPM I asked him via e-mail however never touched on the motor, now you have the wheels spinning, what about Kenny Barnes engine?

It would be better to hear it from Gordon. I'm curious what he tells you.

GPM so far nothing.................cmontell me tell me...........