I'm looking at a 72' motor that has been rebuild to put in place of my 79' 351m, is there any differences between these two motors I should look out for?

 

Never mind, he sold it.

 

. Not much difference '72 to '82... 1971 400" had more power, higher compression ratio, better MPG... compression ratio dropped in '72... about '74 the exhaust ports got emissions bosses in some vehicle models... cam was retarded... 351"M version added... '78 the blocks were strengthened to prevent cracking...


. Really really suggest just rebuilding your '79 351M with 400" crank to 408"... TMI pistons... non-retarded timing chain setup... modern cam/lifters/new springs... to bring your engine tech 30 years into the future... better throttle response... much more power... better MPG...

 

Amen! The reason to go 400 is because there are pistons available to give decent compression. Not so with a 351.

 

Thanks guys, I missed a deal on one 2 days ago, rebuilt 400 motor, never run, high comp cam, edelbrock carb, the guy had receipts from the shop over $3500, he was asking $1000, I was a few hours too late! Oh well, guess I'll keep building mine.

 

Bummer! That would have been a good buy.

 

. He may have discovered it was rebuilt with those crappy 'rebuilder' pistons and decided to start over...