IIn the summer of 1999, I set out to modify the T1 doghouse fanshroud to accept a T4 oil cooler.  Both coolers are identical in how they are constructed with one big change - the T4 cooler has an extra pair of cooling fin rows.  The cooler is deeper so the shroud must have the tin cut and a strip just under 7/8" wide welded in.  The hot air exhaust tube must also be widened a bit so it will fit on the widened dog house oil cooler housing.   This mod will work in bugs and buses but the clearance is really close in a bug.  Some people have had to carefully beat their firewall tin in a tad to get the engine to fit.  The great part though is that the cooler bolts right onto the T1 engine without any further mods to the engine case!  The following photos show how the project went.  The tin has been completely sandblasted and then powercoated gloss black.