the front and rear manifolds on the series 1 motors are just like the rear manifold on the series 2 motor. they are a tubular design but they are welded on the inside. so you need to find someone who can weld them on the outside around each primary and they have to be careful not to heat them up too much or they will warp the manifold flange. after they are welded you need an air grinder or something that you can put a grinding bit in and grind out the welds on the inside of the primaries and smooth it out. hope this helps.
1995 Bonneville SSEi:
(still without a motor and tranny) 15.606 @ 87.95mph (stock)
1998 Regal GS:
DHP 1.0, JMB FWI, ZZP 3" DP, 04 GP 12" Brakes, ZZP 180° Drilled T-Stat, SLP Single Outlet Catback, Silverstars