Diagram attached to this thread.
Vacuum diagram thread

I removed mine and didn't use a welder.
There is a product called Devcon which is a two part Aluminium paste.

I used the Devcon to fill all the holes not just the end ones. Then was able to sand the surface back so it matched the ports.

Just another way to skin the cat i guess.

My car is due back from the tuner this week (New engine and Microtech LT10s installed). probably a good month before i get the power tune done so no figures as yet.

I went bigger (to 20mm) because it's no longer a standard bar, the extra length added to clear the sump reduces the stiffness of the bar therefore you need to compensate by increasing the diameter.

But i agree if you can fit a standard bar then don't bother with increasing the size.

PIGDOG,
I don't want to steal BigV thunder or anything.
But this is the way i did mine

Hi mate,
Ive done a similar conversion on my ute.
It uses the Stanza struts with Girlock callipers. The strut has been cut down 2" to fit 200B inserts (no need to modify strut tops) also kept the same overall travel as the 1200 strut (Shorter insert body, longer throw).

For the disc's I used BMW 290mm ventilated discs, got them as a blank. drilled the correct bolt spacing into them and machined 0.200" inch off the back of the stanza hub.

Same deal as your with the R31 callipers. Drilled out the thread on the Stanza strut, surfaced the back side and machined the calliper mounting lug to suit the disc offset.

With the 290mm disc however you don't need to redrill the calliper mounting hole on the strut.

I just got one custom made through Pedders cost me $220, it was a 1200/120y bar, 20mm with 1 inch extra dip.
Clears the sump nicely.

I agree with LAGWAGON,
I removed the hoses from my throttlebody. However kept the ones at the back...reason i kept the back ones was these are used for the turbo coolent (if we are talking about the same lines), there is a screw in the back ones that regulate water flow/pressure to the turbo, plus the location of the line (high on the manifold) might be for a capilary action (i.e head of water to continue cooling the turbo when the engine is stopped???) so i thought it best to keep them. Anyway food for thought.

Thanks for the comments.
As for the washers yes its all in hand.
As you can see from the pic there are a few things missing. (Mod plate, bonnet latch, washer bottle). The rad support panel isn't painted yet (Has to come out this weekend) so i didn't bother with the washers for this fitment.

I welded two standoffs onto the intercooler that were threaded (Female thread) to lower the intercooler so i can use the bonnet latch), the two hex head bolts infront of the rad bolts are screwed into the threaded standoff's. No bottom support, these bolts plus the hoses from the turbo and throttle body hold the intercooler firmly in place.

Well after a week + a bit work the new engine is installed.

Engine pic

Mods for the engine are:
Forged ACL pistons +0.020"
ACL race bearings throughout
Spool forged Rods
ARP 2000 Rod bolts
ACL multi-layer metal headgasket
ARP headstud kit
Heads reconditioned (Valves were in good condition)
Stock Cams
lifters were replaced
Mild Ported exhaust and intake
All rotating assembly was balanced.
Butterfly values removed, sealed with Devcon and smoothed.
Gates racing timing belt
Lightened Fly wheel
Sprung centre ceramic materal clutch and upgraded (i think 2500lbs clamping pressure) pressure plate.
Stock Turbo Manifold
GT2876r Turbo with T28 compressor housing
Wolf 3d v3 ECU
Peterson oil catch can with Speedflow braided 100 series lines.
Most other lines were replaced with 400 series Speedflow lines.
Firewall fitting is a billet Specialties item (Modified to take 37 Deg flare Speedflow fittings) for the heaterbox.

Stainless Steel intercooler piping
Engine bay was painted (poorly by me i might add) in Devil yellow

Car is going to the tuners this week for a run-in tune so no power figures as yet.

Still to do in engine bay:
New 3" SS intake pipe and new KN filter
Fix fues box lid
Paint rad support panel
Custom front grill