Mods done:cam,crane449601-dur int 224 ex 232,lift-int.542 ex.563
:adjustable 1.6:1 roller rockers
:cobra intake manifold
:1/2 inch phenolic spacer
:GT 40P heads,ported & polished,flowing 400hp
:2500 stall converter
:chiptourque chip
:2 inch twin exhaust
:genie extractors
:24 lb Injectors
:irridium spark plugs
After some advice on what size t/b,maf & fuel pump please.

Get yourself a 70mm TB and an in tank Walbro 255l/hr fuel pump, both will handle those mods with room to move.

Have you run this engine yet, would be very interested to see if the chiptorque can get the thing to idle. Also what have you done to the bottom end?

Standard bottom end,chiptourque advised me that tha standard ecu would handle up to 235 duration.Heads were shaved 30 thou,car hasnt been run yet as im trying to sort out the t/b & maf size.Been reading all the forums on the topic (gone full circle with all the different recomendations)now totally confused.
Going to use a rough program to get me up to their dyno at Nerang QLD thursday of indy weekend,then hopefully be totally sorted out.

Above 220 duration the idle normally gets a bit choppy although newer designs alow that to be pushed to around 224ish. The stock EEC canhandle quite a bit but that cam does seem to be a bit much, but as I said I would be interested to see if they get it reasonable.

The stock bottom end I see being a problem, this cam is designed to be reved well above 6000rpm (the optimum shift point will be somewhere around 64-6700rpm) which the stock bottom end really doesn't like. You at least need it to be balanced and upgrade to some decent main studs to stop the main caps from walking. IMO I really don't think the stock bottom end will hold up to this type of combo.

Also have you checked piston to valve clearance? I had clearance issues with a much smaller cam than that with GT40P's and stock pistons.

Anyway back to the TB, MAF etc. The Cobra intake has a 70mm inlet so going any larger really isn't warranted, plus the 70mm TB also flows enough for 340kw. I would look for a 75mm+ MAF calibrated to your injectors. And the Walbro 255l/hr in tank pumps are cheap, easy to install and flow enough for 600hp+.

Would a bottom end stud girdel help the main caps from walking.Fingers crossed the bloke who did the heads checked the valve clearancese out & said it should be right.Would a 65mm t/b & 70maf be sufficient.

Yeah a 65mm TB and 70mm MAF should still be fine, both flow enough for 290kw.

Stud girdle won't help in this situation IMO. The main cap bolts are apparently fairly ordinary and the stock balance is not exactly great (+/- 6gm from memory). IMO it really is only good for 5500 with the occasional burst to 6000rpm. I personally wouldn't want to run over 6000rpm very often but the problem you face is that with a cam designed to make peak power at 6400rpm, you will sort of be forced to rev it that high quite often.

Doing the main cap bolts isnt a majour hassel as the motor is out of the car still.Whats a good option for bolts.

Should really go with studs but they generally require the main tunnels to be line honed. Otherwise get some decent ARP bolts.