Bolt hole sizes in marine blocks and passenger car blocks

Discussion of the Marine / Industrial Hemis.

Moderators: scottm, TrWaters, 392heminut

Post Reply
budmspeeco
Posts: 133
Joined: Tue Dec 21, 2004 5:35 pm
Location: South Houston, Texas

Bolt hole sizes in marine blocks and passenger car blocks

Post by budmspeeco »

I am trying to mount an alt. on a 331 marine block using the lower bracket from Hot Heads. One of the bolt holes in the aluminum bkt. is a 5/16th that bolts to the front of the block , with the bolt going through the Hot Heads aluminum timing cover. I did not realize until I started the attaching that the front of passenger car blocks have 5/16th bolts holding the cover on and this marine block is 3/8th size. Perhaps the industrial blocks with the lower hole in the front and '51-'54 early blocks are the same. I can only guess that others have encountered this . If not, just be aware of this difference when purchasing after market brackets. I am going to call Bob Walker tomorrow to see if I can just bore the bracket to 3/8th , or if it will fit at all. Buddy
I just posted this in the 331/354/392 section and thought the readers of the industrial/marine section might want to think about the bolts sizes in their blocks if they were to try to use an aftermarket bracket. I will give an update after I talk to Bob at Hot Heads.
'48 anglia
Bailiesdad
Posts: 433
Joined: Sat Dec 01, 2001 6:00 pm
Location: Maryland

Post by Bailiesdad »

"Perhaps the industrial blocks with the lower hole in the front and '51-'54 early blocks are the same."

They are the same and Bob probably has the correct bracket, just order the correct year parts.
Post Reply