I have read alot about the major problem with power in the b18 is the evacuation of gases thru the exhaust system. This i guess can be overcome in a lot of different ways, some of them very costly, at least for me, such as Porting and polishing, headers of the 2+ inch variety. But i have seen a little on this site about the double downpipe manifold that came on 67- 122s bieng placed on instead of the earlier single pipe exhaust manifold.

I was just wondering if this was a cheap reliable way to go, as i picked one up out of a graveyard of volvo parts. Recently someone asked if they had done this conversion in relation to a SU question, if memory serves.

Does this type of alteration require a recalibration of the fuel system, i.e. different mixture, SU needles, Valve lash, or can it be cleaned up and bolted on and driven?