My buddy is doing a rebuild of his 928 engine. he has a 4.7L M28-11 euro block and was going to put on a set of rebuilt 4.5L US heads. Does he get a head gasket for a 4.5L US or a 4.7L euro or does it matter?

 

you need 4.7, cylinder wall has a bigger inner diameter.

 

thought so, thanks for confirming

 

If you want to wait before you put those 4.5L heads on I have 2 sets of heads and cams in cam carrier for a Euro S 4.7L . One set is off of a 1982 M28/11 and the other set is off a 1980 M28/12.
I am in the process of deciding which set to use and soon the extra set will be for sale. Your friends Euro S motor will be a lot better with these heads and cams especially if you have the Euro S intakes. 300HP. Gunar

 

His car is a 4.5L US Model L-Jet. Would complete euro motor drop in or will there have to be changes made?

 

Easiest option, keep the intake and injection and put them on the Euro block and heads, should have a nice bump in power, but with a truncated top end.

Find a set of 84/86 Euro S intake and fuel injectors and marry that to the Ljet brains and air flow meter. You might need an adjustable fuel pressure regulator to "tune" the air/fuel ratio.

Middle option with Jjet air flow meter replaced with a MAF and either use a MAF calibration box (John Kuhn worked out how to do this for his turbo package), upgrade to 85/86 brains and sharktune.