1958 348 ci block stroked????

[kart34]

Can a 1958 348 ci block be used to build a high end stoker motor? I have purchased a set of 425 hp 409 heads also . Can they be used with this block? I was told at a recent Good-Guys show that the 1958 block was the most undesirable block to use. Please help?????? Thanks, Greg

 

[oldskydog]

Can a 1958 348 ci block be used to build a high end stoker motor? I have purchased a set of 425 hp 409 heads also . Can they be used with this block? I was told at a recent Good-Guys show that the 1958 block was the most undesirable block to use. Please help?????? Thanks, Greg

Greg,
The short answer is yes it can be stroked.I believe there are several members here that either have or are in the process of building such an engine. Probably the best source is Aubrey,( CDNpontiac409guy). He has all the info you will need and also most if not all of the parts.
As far as your block if it is the early 3751872 casting it can only be used with the early 3732791 heads as neither the block nor the heads have provision for spark plug cooling. If you have the late 58 block casting 3755011 you should be able to use any of the later heads. I'm certainly not an expert but there are plenty of guys on this site that are. I hope this helps.
Cecil

 

[kart34]

Cecil, I have the early block part# 3751872 . Can it be modified for the big heads?

Thanks, Greg

 

[MRHP]

modify

I believe the 690 and 583 heads will not go on the 348 due to the exhaust valve opening towards the cylinder wall and hitting it. If I am wrong someone please correct me.

 

[oldskydog]

Greg,
Somewhere on here I recall reading a thread that discussed that problem. It seems that if you welded up the cooling holes on the later heads it might be possible but I don't recall all the details. As far as valve clearance I seem to recall a posting about cutting a relief in the top of the cylinder. You might do a search on the subject. I'm sure the guys that know will respond.
Cecil

 

[Bungy]

kart34, some of the 3751872 blocks had provisions for spark plug cooling but were not drilled. I know because I have two 872 blocks and one has the provisions and the other doesn't. If you have this type of block all you have to do is drill out the "pads" and install the later type heads. Almost every 348 block made has the notch at the top of the cylinder by the exhaust valve so the large valve heads can be used without worry of the valve hitting the cylinder wall.
I see you live in Medford. I work in Owatonna. If you want I could swing by one day and take a look at your block and let you know what type you have. If your interested send me an email and I'll give you my phone number.