Reetting 350 Banshee Overbored to 65mm

[Texaco350]

Hi all,

I just rebuilt my motor over the Christmas break, and I'm hoping someone can help me in sorting out what jet's to use. The current setup is as follows:

 

Carb: Main Jet 280. Pilot 25 (Stock) Needle clip on last position. Also V force reeds.

 

Engine: New crank with +4mm Stroker, Cylinders overbored to 65mm with Wiseco pistons ans rings.

 

My problem is when I open the throttle beyond 1/4 it boggs and starts banging and misfireing, I moved the clip on the needle down to the last and when reving the engine i pull out the choke, it definately made a small difference so I think i need bigger mains? does this seem correct?? what size do ye think I should begin with if my thinking is correct?? Would i also need to increase my pilot jet's?? it seems to tick over nice a smooth as it is with the stock 25's and run smooth to just beyond 1/4. The air screw is at approx 1.75 turns out. Any help would be greatly appreciated.

 

Oh my elevitation is about 350 - 500ft above sea level and the current temp over here in IRE is between 4 and 10C.