408 stroker only 210 HP. HELP please.

[Rhauf]

Well, let me first start by saying that im a bit new here.. i've been registered since 2001 or so, but only sometimes lurked and i haven't posted any untill now. i tried posting this earlier today but i dont think it went through, so if this is a double post, forgive me. anyway, i have this new build which has been giving me some trouble, so i thought i'd ask and see if you guys have any insight on it.

It's a 351W roller block, stroker crank, forged pistons at 10.0:1 compression. edelbrock RPM heads (170cc, 2.02 intake) crane hyd roller cam 224/232 @0/50, 560/540 lift, 114lsa, roller rockers, dual 2.5 inch exhaust, edelbrock 750cfm carb, and mallory distributor.

its a new build and it has about 600 miles on it now, so i took it to be dyno tuned, and it showed up as running lean, and only making 210 rwhp. drivetrain is a c-6 w/ a 9" rear. i upgraded the fuel pump to a 110gph 8psi mechanical (from the stock mechanical) and regapped the spark plugs and it's running a little better now (perhaps the lean condition was caused by low fuel pressure?) i havnt dynoed it again, but i dont expect it has gained more than 50 more horsepower. still well below the 400 rwhp that i was hoping for when i built it. any body have any ideas, what is a realistic expectation for horsepower from a build like this?

thanks for reading