92 SCX Exhaust Manifold Glowing RED!

I am trying to figure out this problem before I go any further with performance tuning this car. I want to know what the stock Casting # for a '92 SCX Cylinder Head should be? I think there have been a couple of hands in this thing before I bought it.. I want to put it back to stock or better, before going any further.
Thanks,
Al

Here is my problem: the car idles somewhat OK, Sluggish off the line, It does Pop through the exhaust between shifts (I have now removed the Cat, Pops less), It don't produce any real power untill 3300 Rpm's, And the exhaust Manifold Glows Bright Red (Before and after having a Cat)! I hear that the head was replaced, No one knew if the cams are still stock (w41), after head replacement the bottom end went out, Now rebuilt short block with supposed new head, he drove the car for 3 months and the oil pump went out - I bought the car. I put in a new Oil pump and pickup and I found all the problems stated above, contacted the former owner to get as much history as he had.

Timing chain looks new, and the guides are not worn. I checked the vacuum - It is low bouncing between 12 & 15 inches. No vacuum leaks - Sprayed an entire can of throttle plate cleaner at the intake and throttle body gaskets with no flutuation in idle. I did preasurize each cylinder, with no known valve leaks.... I replaced the Fuel Pressure Regulator, Map sensor, O2 Sensor, and about to replace the white coil housingwith a new one... I just pulled out the chain and cam Gears - Are the Intake and Exhaust Gear supposed to be Identacle? I am STUMPED, any help would be Great.
Al in Milwaukee