348-what to do, what to do

[rarerodder]

I finally picked up my 348 last week and I'm ready to start the build. Here's the numbers: block: 3857655, heads: 3732791, intake will be a Offy 2X4. I really enjoyed the feedback to 4d9r's "Build a 348 on $3500-How would You?' thread. But, I must say, I'm still not sure what to do to accomplish what I want. Like 4d9r, I'm building a streetrod but in this case a 3200 lb Hudson. It'll definitely see alot of highway miles with the AC on and I'm 95% sure I'll never be racing the big coupe (there's always the 5% chance I'll get a little squirrely); but, I do want my buddies eyes to widen :eek: when they hear the motor crank and when they take their first 'test ride'. So, I'm posing the question again: what needs to be done to the old stocker to make it respectable and dependable? Stroker? Cam? Ignition? Change heads? I bet one of you guys have built the motor I'm looking for already. I'm all ears here. Oh, I'll be mating to a 700R4 that's already in the works.

 

[models916]

leave it 348

Get forged pistons, BBC rods and composition head gasket, Comp cam, Serdi valve job, BBC roller rockers, roller timing chain. Lots of horsepower in the tune of parts. 348s always ran good. Seems there is lots more in them with the right pick of parts. Check with the Canadian guy for parts, he should have a combo that works.

 

[johnnyrod]

I just learned a lesson and that is I should have got my cam and then got my valve springs to work with my cam. I have 333 heads. My point is homework does pay off. My buddy said to me years ago its called dallar hp. Looks like you are on the right path. Just my 2 cents John

 

[oldskydog]

I would look for some different heads. Your 791 heads were the first version from 58 and don't have the spark plug cooling provision. They are not compatible with your block unless you block (weld) the water jacket holes in the block. Any other heads should work.

 

[SS425HP]

Good Eye, Cecil

Good thing you noticed that, Cecil. I knew about the early heads, but never paid any attention to the numbers. Saved a friend of mines butt a couple years ago. He was working on a 58 for one of his friends, and put new plugs in it. I asked him if he put the short plugs in, and he said no. He had the long reach plugs in the early heads. Don't know for sure if they would hit the piston, but it would have to be close. He put the short ones in. All was OK, then.

Rarerodder, make sure you check your block. If it has the cooling holes, you do need different heads. Check with a head gasket. The holes on the gasket should mate up with the block, but not the heads in the spark plug area. Should be 2 holes at each plug area in the gasket and block, which won't be in the heads.

Good Luck

 

[3483x2]

"I finally picked up my 348 last week and I'm ready to start the build. Here's the numbers: block: 3857655 , heads: 3732791, intake will be a Offy 2X4."

Checking your 3857655 info against the database, I see there is no such block number listed. (Mis-key? I do that all the time)
There is a "3857656" block listed and reported as a "64" 409.

Either way, use caution matching as the 3732791 heads are unique to 348 non-water jacket blocks as others have already reported.

Best of luck with your project.

 

[rarerodder]

Casting Numbers

I thought the same thing. I couldn't find the -655 block number in this website's list and thought it must be -656 (409). But, the number on the block is definitely -655 and now I have found on the Mortec website www.mortec.com/wmotor that the 3857655 number is listed as a 62-65 348 truck block.

I'm pulling the heads this weekend to confirm the water jacket mismatch. If so, anybody got a good set of big valve heads for sale?

 

[4d9r]

The feedback I got from the guys on this forum that responded to my questions regarding the 348 build were

sound and gave me enough information to be able to talk semi-inteligently when I called Curt Harvey in Palm desert Ca. I would suggest you talk to Curt before proceeding as I can't imagine you won't learn some stuff from that conversation. He can recommend what to do, what parts to use and will help you where you need help. Nice guy who's been building these "W" motors for years.
Terry

Curt Harvey - www.mr409.com

 

[Mark Mallek]

I have a similar issue - I rebuilt a Block with casting # 3732811 and I rebuilt Heads# 3758379. I am looking for a set of heads 3732791. Maybe we could work something out. Mark email is dmallek@tznet.com

 

[bobs409]

I must confess, our casting number section is a mess! After I bought the "Chevy by the numbers" books, I redesigned and changed alot of the numbers and there since then, learned it has alot of mistakes. It may be a while until I can redesign and check all the numbers but if anyone can help with them, it would be appreciated.

It seems like one books says this... and another says that. I'm at the mercy of them as I don't own samples of each.


Bob