'69 340 rebuilt, now it runs hot and power is down. ???

Just wondering what you guys think of this motor/transmission combo.  Before I rebuilt everything it was a totally stock numbers-matching 275 HP 340 that came in my ’69 Dart GTS.  Since it had iron heads and 10.5 compression, it pinged on 93 octane pump gas. But it was a very strong motor that had great response and never got above 180° on the temp gage.  Now that it is rebuilt using the parts/specs below, it runs hot (get stuck in traffic for 5 minutes and the temp goes right to 220°), and seems to have a lot less power/response.  One good thing is that now it never pings on 93 octane. Here is what I have now:

’69 340 block, crank, rods, .060” oversize 10.5:1 pistons, all clearances are to stock specs.
Edelbrock Performer RPM “340” aluminum heads #60179, 65cc chambers.
.038” thick Corteco head gaskets. New ARP head bolts.
Comp Cams adjustable steel roller rockers & new shafts.
Comp Cams #20-309-4 cam, 268°I/276°E, .464” lift, 110° lobe sep., installed straight up.
Rhoads hydraulic lifters. ½ turn pre-load on lifters.
Edelbrock dual-plane Performer RPM intake manifold #7176.
Holley 650 dual feed, vacuum secondary carb #80783C, out of the box.
Carter hi perf fuel pump. New lines, new filter.
Stock 340 HP exhaust manifolds, heat valve removed, ceramic coated, with stock dual exhaust (none of this was changed).
Mopar Performance electronic ignition kit.  Timing is set to 36° @ 2000 RPM with vacuum disconnected, vacuum advance is adjusted per Mopar’s instructions for 52° total.
Milodon high flow 180° thermostat.
Stock 3.23 posi rear end (this was not changed).
Hughes #44-20 “Street Rod” 2000 RPM stall converter.
727 TCI “Sizzler” transmission, B+M fluid.

Did I go wrong somewhere? It should have more power than stock!  

For a street car .060 overbore is a ton on a motor that should likely never been bored passed .040.
I know they sell pistons for the bigger bore but they are usually for guys that are drag racing and filling the block with hardener.
To correct the problem I would go with the largest triple core rad I can find or a large aftermarket aluminum rad.
You will need extra cooling were ever you can get it, so install the largest trans. cooler you can find as well.
Run a 160 thermostat and a factory clutch fan with as many blades as you can install on it. Summit sells a number of great 7 + 8 blade fans for a clutch unit.
Timing for the 340, 10 degrees initial, 34 degrees total, when hooked up to the vac. advance I would recommend using an allen key to turn the vac. diaphram in as tight as it will go. This will limit your total advance with the vac unit.
48-50 is a good total number.
Just for fun I would also suggest installing 2 jet sizes larger on the primary side of the carb, good chance this vac carb out of the box is way to lean for your mean machine.
Good Luck Doc  

Thanks for the ideas Doc. I have the good factory fan, and the shroud is still there too. I hear you about the .060 overbore. I didn't do that, and I'm not too sure why the previous owner went that big. Will bump the timing back a degree or two and try the jets, thermostat, and maybe put a good electric fan on the front side of the radiator.  Unfortunately it is starting to get cold here in New England so I'll have to wait until the hot weather comes back before I'l know if it's really fixed!  

Sounds good, the timing is critical on the short stroke 340, a 360 can us a little more but not much.
Good Luck
Doc  

are the pistons cast or forged? forged run more clearance than stock. from .030" to .060" the wall is only .015" thinner , not a big diff. on how hot it will run. cam is a good choice for a single step up from stock, kinda small for rhoads lifters. try your old carb. with vac. advance disconnected u want 35-36 degrees TOTAL advance which is not usually as low as 2000rpm. do u have 43 degrees at 4000rpm? the changes u have made should not reqiure a giant upgrade in the cooling system. it is not that cold yet in new england, check total timing = revved up, try a cruise with less vac. adv.(or even disconnected for testing) and get back to us. I run 1970 duster with a 340 bored and stroked to 360 with a true blueprinted 11:1 and a big cam and ported iron x heads and a 440 magnum avs jetted up with a stock radiator, stock water pump, cheap old fiberglass fan (probably costing me 15 hp) small moroso lower pulley-for those 7000rpm blasts, on 93 octane on the streets of Mass. running an average of 185 degrees and 11's at NED.