What's the max bore and stroke a late model gm 350 can handle?

[Big-Blue]

A friend bought a 408 stroker from a reputable shop in NC about two years ago and hasn't found the time/funds to finish his build. It is sitting in its original wrapping. He wants to sell and the original cost was over $5k. I think he will sell it for about half of that. It dynoed around 500 hp/tq.

Question: How much bore and stroke is too much for that block?

My 71 K20 will be a truck driven for fun meaning occasional mud and hauling, but maybe some 100 mile trips here and there - in Texas. No track time obviously. I want the ponies but want it to be reliable at the same time.

Thanks for any thoughts as to clearance, overheating issues or anything else I should be wary of! (the warranty is up on it as well)

Here are the specs:

Bore and Stroke - 4.030 x 4.000 Inches
Compression Ratio - 10.5:1
Fuel - Premium pump gas
Crankshaft - 4340 Forged Steel (two piece rear seal)
Connecting Rods - 6.0 Inch Forged H Beam, bushed
Pistons - Forged
Rings - File fit plasma moly
Block - GM 350 late model roller, your choice of color, 4-bolt mains
Camshaft - Hydraulic roller
Lifters - OEM style hydraulic roller
Timing Set - Double roller chain
Timing Cover - Chrome
Harmonic Balancer - Professional Products
Oil Pump - Melling standard volume
Oil Pan - Stock style chrome
Heads - 200cc Dart Pro 1 Platinum, 72cc chamber
Head Bolts - ARP
Valves - Stainless steel 2.02 Intake 1.60 Exhaust
Springs - Dual with dampner
Rocker Studs - ARP 7/16 diameter screw in type
Rocker Arms - Aluminum full roller, 1.6 ratio
Pushrods - 5/16 Hardened steel with guide plates
Intake Manifold - Aluminum Edelbrock RPM Air Gap
Valve Covers - Chrome stamped
Spark Plugs - Autolite 3922
Oil Filter - Fram PH5 or comparable
Ignition Timing - 32 degrees at 4,000 RPM
Oil Type - Mineral based


Labor Details
All parts hand cleaned
Block sonic checked for thickness
Block pressure tested @ 40 psi
Block stroker clearanced
Block square decked with BHJ fixturing
Oil gallies tapped for screw in plugs
Aligned honed mains
Bored and honed with torque plates
All clearances checked to the nearest .0001"
Rotating assembly balanced
Engine blueprinted with specs sheet on file
Engine fully dressed to customer specifications
Dyno tested with actual results supplied to customer
1 year 12,000 mile warranty