I finally got a hold of my old motor from my 91 z28. It had a 305 tpi motor and when I took it out I noticed that it had aluminum heads. Can anyone tell me if the numbers I got off the head are in fact Gm head the number is 14101081 the motor was a 5.0L G SGI thanks for the help

 

www.mortec.com

 

081 is right for a 305 TPI... but aluminum? wtf?

 

The heads look like there aluminum bright and silver looking and smooth.

 

Got any pics. Because the 081 casting # is right on for standard 305 TPI heads for that year.

 

Im flying out tomorrow to Memphis from Seattle and I wont be back for a week, after that I can take some pictures, also whats different that my magnet wont stick to the heads???? I guess I need to get into more details before I ask anything else. Also under the 14101081 number was the number E080 I figured that must be the date or something. Thanks for the help

 

If a magnet won't stick to them, then it's not a magnet. Those are, without any question, cast-iron heads.

You guessed right; E080 is indeed a date code. It stands for the 08th day of the Eth month (5th, or May), in a year ending in 0 (probably 90 for that particular casting, since it wasn't available in other years ending in 0). May 8th, 1990. Considering that it usually takes from 2 to 4 months for a casting to make its way from cast to installation in a vehicle, looks to me like those are consistent with being the original ones for your car.