I looked in NHRA stats . only heads allowed are894, 915, 596,051,587,974,308,576,302. all are iron heads!! the edelbrock heads are listed, S/S only 60767 casting. edelbrock states, S/S only use also. the foot notes in NHRA stats, didn't show alum heads for340 for stock. they are quite specific about casting numbers and allowed items. they showed alum heads for the hemi engines and some383/ .440 engines. this was for 1970 year.
