Its a few weeks off yet but i want to have all six pipes exiting the engine bay so my manifolds will need a bit of modification.
How are manifolds modified without distorting them? Even the slightest amount of distortion could cause a blow.

Bolt the flange to a scrap head, or a stout jig, peice of RSJ, heavy box etc. to prevent it distorting.

Dont do too much welding in one place, to prevent local heat build up.

Take your time and let each bit of weld cool and settle before moving on...

[Edited on 6/3/09 by r1_pete]

wot r1_pete said. also if you are bolting manifold fange to a heavy peice of steel its a good idea to tack weld it on as well you can easily grind it off and tidy it up when you've fnished. m.