Charlie is an American living in Spain and was having the work done
by a shop in France. He was looking to run the car at triple digit
speeds for extended periods on unresticted European highways. His
Pantera had a stock block that he wanted to retain (cast dished
pistons) so I suggested the following build:

Aussie 2V closed chamber heads
Weiand Xcelerator 2V intake
Holley 700 DP
Comp 282S solid lifter cam
Hedman Pantera headers (1 3/4" primaries, 29" long, GTS collector)
Roller rockers
Double roller timing chain
Moroso oil restrictors
10 quart Aviad road race oil pan

I don't think Charlie shopped around much but based upon the few
shops he called, he didn't think he could beat Powerheads price on
sourcing the heads and doing the machine work (valve job, mill and
drill for studs and guideplates). He opted for their port job with
4V sized valves. I sent the Weiand intake to Powerheads for Charlie
so they could port match to it. I also strongly suggested that he
run 2.1"/1.65" valves instead of the 4V's and told him to order a
complete Comp Cams kit though Alex so he'd be sure to get the right
springs. Powerheads talked him out of both suggestions, installing
their own springs and 4V valves. This came back to haunt Charlie.
On a long, high speed trip, Charlie experenced some valvetrain
problems (rockers backing off, bent pushrods and ultimately a bent
valve). The problem turned out to be the Powerheads springs. That
error caused him a lot of time, money, and grief. While it was
running, Charlie was very happy with the engine combo, though.

Another guy in the club used Powerheads, again because they could
source the Aussie heads so cheaply. This time it was for a Mangusta
with an overbuilt Boss 302. Steve wanted to tame it down some for
the streets but wanted to keep the Boss 302 look so he decided to
do a Street Boss conversion. I let him talk me out of my intake,
suggested a Comp 270H cam, and he ordered up a set of Powerheads
Aussie 2V heads. When he received them, he noticed they were two
different casting so he C'd the heads and sure enough they weren't
the same. Powerheads did make good though and exchange the head
for a matching casting.