I noticed there was a question mark on the Detroit Series 60, these motors are also DD Alpine Green, at least all the ones I sat behind were! The Kenworth Aussie is not the only kit Revell AG did not do their homework on either! The "Can Do" wrecker is grossly inaccurate. The kit has a Cummins, the real truck has a Cat 3406, I think. The rest of the truck is based on their Pete 359, and there is many differences between that and the 379! I think I've also seen one engine in resin everyone's forgot, the M11 Cummins (even though why would you want one) and these were painted black. The IH/Ford engine one of you mentioned, were you talking about the larger engines or the pickup engine? The 7.3 Liter in the Ford F350 at least in 1990 (like my 1:1 dually) is gray.
I promise, there is gray somewhere under all the grease and grime, the motor is 20 years old!