I'm trying to figure out the specs for the block that is in my active thunder. The flame arrestor cover was for a 454 mag motor. When I looked up the serial number on the block the results were for the 88-91 7.4l bravo. Does anyone know if this is a mag motor? Also where can I find the specs for it as far as rpm range and HP?

post the serial number on here. there are guys here who will tell you for sure right off. look at intake manifold though. is it a high rise with large looking runners? or is the carb flange way down between the mating surfaces to the heads with smallish looking runners? the main diff is internal- steel crank, better rods, forged pistons, rect port heads, more cam. but the most obvious diff is the intake manifold.

Serial number is 0c754611. It does not have a high rise intake so in thinking it is not a mag but if anyone has any input as far as the specs for this serial number it would be greatly appreciated