Can anyone tell me what year and engine heads with part number 3998993 which on one head it looks like 3998983? One head has P253 on it and one has P153 .....?????
Thanks

 

Looks like:

3998993....72-73...307/350......75cc chambers
3998993....current..350.........Goodwrench crate motors,"Hecho en Mexico",75cc chambers

[align=left]So, if they are 34 year old heads, they are original from a 307ci (most likely a truck) or 350ci factory engine. If they are newer "Hecho en Mexico and pass the tequilla senor" heads, they are likely on a less than 5 yr old crate motor.

[/align]bill

 

so it's no way they are corvette heads?

 

Bill that casting number does apply to some other cars, but is was a casting number to a 72 vette 200H.P.

 

Run those numbers through www.mortec.com , it may help.

 

Absolutely Copley, those numbers correspond to a generic 72/73 small block chevy. It could be in a Vette, a Camaro, or a Malibu station wagon.

bill.