Want to build a maximum 348

5

58Imp348

New Member
Hey all! I've been researching which 348 casting has the thickest walls. I'm definitely buying aluminum heads. Still unsure which route to go on the stroker. If I should just buy the $2200 kit or try and put some other combo together. I want to run a radiator so no filled water jackets.

Nexr, Headers...Should I go tri y? Looks like the only fenderwell headers are the Jardines.

This may sound out of order but I usually try to start planning in the middle. That way I don't get myself into a corner.

The project is an old 58 Impala sport coupe that is too far gone to restore to original. I want to make a gasser. Maybe a 4 speed on the column.

Any help is appreciated!

R
 
Dick MacKenzie

Dick MacKenzie

Well Known Member
Supporting Member 9
Tom Kochtanek

Tom Kochtanek

Well Known Member
Supporting Member 13
With regards to 348 blocks, thickness can vary across the various sand casting pours. Some have noted large bores on early blocks, but my guess is that the "last generation" of 348s, those with the "655" castings, might be a good starting point. I think someone here has bored a 348 block .125" over, which is quite large. I bet the "962" service replacement blocks would also be good candidates.

I have one of each, but never had them sonic checked. Perhaps others have?

Good luck with your build, and keep us posted on your progress :).

Cheers!
TomK
 
jim_ss409

jim_ss409

Well Known Member
Supporting Member 5
We bought the stroked 348 that Joe Sherman built for Hot Rod magazine. I think it would be a good guideline to follow if you're building a max 348.
You could drop the compression down to 10.5 and use a little less cam to make it more street friendly. It would still make over 600 hp.
Or, you could use a set of Bob Walla's CNC ported heads and get even more power than the 650 hp that the original engine made.

That engine ran very well. I think it ran a best time of 10.37 in my 55 Chevy.
We did have a cam failure with it. At the time the engine was built Crane Cams had gone out of business and Joe Sherman had to get a cam core elsewhere and have Comp Cams grind it. The cam was ground below the level of the heat treatment and eventually failed.
We later put all the stuff from that 348 onto a 476 ci 409 and it's still running in the car today.
When we pulled the 348 apart I looked closely to see if there were any signs of the main caps moving and they looked just fine. That engine was the built using an early 1958 block which is probably the weakest 348 block there is and yet it was holding up just fine to 650 hp.

One thing that I should mention is the lifters mentioned in the article are not the right ones. It had standard length lifters not the +.300 lifters.
 
303Radar

303Radar

Well Known Member
Supporting Member 2
How are you defining "Maximum"? I'm rebuilding my 348 with at 20 over and a 4" crank. Using Aubrey's heads at nearly 10:1 compression and a bullet cam shaft. Also using Bob's Aluminum heads. With the coil packs and fuel injection I'm planning on using, I'll probably be at mid 400 hp before adding the Pro Charger. If the numbers from Pro Charger are correct, I should be able to get 60% increase of power with 1 psi/cylinder, getting me to low 700 hp. I doubt I'll rev high enough to use the 700 hp, but I'll have it on reserve :brow

Good luck with your build!
 
61 Bubble

61 Bubble

Well Known Member
58, need to know more about what you want/have and goals FIRST. Also filled waterjackets work fine on a streetcar or if your running a rad, just DO NOT fill past the water pump holes! Help add some rigidity to the bottom of the block yet still lets you cool the important areas. BUT this is from BBc knowledge and these motors "might" need a bit more, but I doubt it.

Alum heads = Bob Walla hands down.
Headers??? IF you go the gasser route, go FENDERWELL if just normal any large tube 2+" from Showcars should be fine.
 
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