Forget the sohc or dOHC 4.08" Barra as an expensive joke if you are adding the cam drives, although its possiable.
The Krogdahl heads were 4.08" unifit OHV 250 fORD or 186.202 Holden.
but your in luck with cam in head pushrod. Your name is OpelGT+3point3, so try some old 1900 Opel heads. See below, 4.125" I think. Germans just throw those old 2.5/2.8/3.0 and 3.6's away.
But its like finding common pistons in the 3.68 to 3.76 sizes, or comon rods in the 5.88 to 6.125" sizes, the industry doesn't make engines at 4.08 anymore.
Bearing in mind how Austin and Jaguar would repitch its cylinders in the factory to turn 1100's into 1275's,
or 3.8 into 4.2's, to 3.8125" centres
Before cutting and welding, anything is possiable with a margin of +/-1/16 of an inch. So 4.0175 to 4.1425 or maybee a little more, you can repitch bores, or relieve the bore ledge to allow the valves to avoid ledging. And cut and shut weld like the 4,375 to 4.48" difference in rewelded BOSS 302/ Cleveland to 300 blocks
My old mate Jermey D from Victory Library does this stuff in his sleep.
Nothing but the Holden 149/173/179/186/202 is the same.
2.3 Volvos and 2.0/2.3/2.5 Limas average 4.17",
Don't mess about with S or DOHC, stupid idea.
Edit:02-01-2017
http://www.allpar.com/mopar/47.html
The 4.7 Liter “Next Generation” and “semi-Hemi” V8 Engine (Dodge - Jeep) ... The bore spacing is reduced from the 1955-1998 small block's 4.46 to 4.09"
The OHV Mopars 5.7/6.1 SRT Hemi has the old LA V8 bore spacings of 4.46""
See
http://victorylibrary.com/mopar/bore-center-c.htm, error in line 3 , THE 5.7/6.1 IS 4.46, NOT 4.09"
Ferrari/Maserati V8's and Ferrari V12's from 2003 onwards are about the same at 104 mm, BUT 5 Valves PER CYLINDER.
Before that, Fazzes had smaller Colombo or Lampredi spacings
on the Lampredi engine, 4.25"(108mm), same as the Nissan 1984 on wards VQ30E
Colombo, 3.543"(90 mm) first, then revised 3.700" (94 mm),
The Lamborghini based his totally original Bazarini LP350 engine on the revised Colombo crank billet, but with 3.74" spacings(95 mm).
TRAILBAZER cHEVY GM 4200, 4.045"
EAO OHCS, 4.0157, same as all the other Duratechs. VOLVO 60 degree V8's and V6'S are SHO Yamahas, as Ford bought the engine design from Yamaha
Modulars/Romeos, 3.937.
Center section of 1985-2003 sohc/dohc RB Nissan L6s and 1968-1985 SOHC L Datsun sixes are 3.97", but outers are same as the 1959 to date Kent/Valencia/Endura Ford Pinto pushrods at 3.76. BDA/BDT's are based on that kind of block, but alloy.
In 1968, Datsun did he six it that way because the Chysler Slant six has 3.95 and 3.97 bore spacings right thru or something like that, and they didn want to be seen to be copying the Ford Zephyr Six which also had 3.76" bore spacings uniform. .
The Datsun 4cyl L series and NAPS Z's 3.76 centers are nearly the same as Kent/BDA Fords 3.78, and the Mazda made MZR Duraetech 2.3/2.5 4 cyls, rehashed BDA's with Mazda design features. No wider spacing in the center. Just super short stroke 1959 105e bore spacings, which was the British Ford Zephyr 6 bore spacing. Holden Grey motors (130.5-138 cubic inch, based on a preware Chev six that didn't see the light of day) used the same 3.76" bore centers as the later 138 Deap Skirt Vauxhall and Victor FD 97 cubic inch pushrod fours.
Old stuff like Lotus is just OHC Vauxhall Firenza 4.125" in alloy.
The old Opel 1900, 4.125" as well, or near to. Same as the related 6 cyl block, the Vauxhal Calton 3.6, Opel 2.5/2.8/3.0, or Bitter 3.9.
The average bore spacing of the even fire 3.8/4.2 Essex is 4.1875", but the block is slewd left to right bank to remove rod offset and add a fillet between the two journals, so the 4.48" bore BUSCH engine is uniform without the fillet, because its odd fire. My understanding is that you could repitch one form the other, it wasn't a dead end concept like people think. But head pitching on the 3.8/4.2 is nearly as big as the Buick 225/231 GM 3800 V6 and BOP 215-300 /ROVER 3.5/3.9/4.2/4.6 and LEYLAND P76 at 4.2125" or so.
Huricanes, or whatever Ford calls its OHC 6.2 TRUCK, 4.52 OR SO
Other info:-
/viewtopic.php?f=1&t=70602
http://vb.foureyedpride.com/showthread. ... ost1585630
http://vb.foureyedpride.com/showthread. ... his-engine