Macs 348 Build!

#1
I just picked up a car with a stock 348 it's a 62 truck with the 33 heads. I am currently running 3 dueces but I have a offy manifold with 6 Holley 94's that I am planning on going to later. My main question is can I get more performance/sound with a cam for this motor with out doing anything major.

Thanks
 
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Don Jacks

Well Seasoned Member
Supporting Member 3
#2
Yes,but don't go any bigger than 219@.050 on the intake if you're running the stock pistons.There are two reasons for this.One,anything bigger will have piston/valve clearance issues due to the amount of overlap.2 is the rpm limit,if you expect it to live,is 5.500 max.If you're going above 5500,you need forged pistons,period.DO NOT even think about Thumper,Bootlegger,or any other simular "sound" type cams.These engines don't like them[drivability,poor mileage],and in all likelyhood neither will you.
 
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1964SuperStocker

Well Known Member
Supporting Member 2
#4
ENJOY the 348 and learn for now. Stroking isn't to hard but there are a number of things to consider beyond performance like class and style. Don't spend all of your money on high end parts if all you are going to do is drive around to car shows. If you plan on racing then open that wallet wide or know enough to do most of the work yourself.
 
#6
I found a isky with .208 @50 and 488 lift. Seems about as big as I can go. Thats not enough to rock my boat Sooo.. I might just wait on the cam. Don't think I can run enough cam to make me happy. Maybe next winter port and bigger valve the heads.. high compression pistons. I am not a really much of Saturday parking lot show guy. I am a more show and go at the drags guy.
 

Don Jacks

Well Seasoned Member
Supporting Member 3
#8
Fyi,a cam for what you'd like is the Show Cars 0950 cam.Adv.duration is 262 in.,270ex.,at .050 is 218 in.,224 exhaust,with a lift of just under .500.Your source of information is mistaken.This is a sweet little cam,great low end and mid range,a power peak at about 5,000 with manifolds,better with headers.
 

Don Jacks

Well Seasoned Member
Supporting Member 3
#12
It's not lift that's the problem,it's overlap.The maximum duration on these 348 engines is 220 @.050 when they're equipped with the base 9.5-1 compression ratios.You'll need to change valve springs as well,but your stock rocker arms and push rods will work.I can figure the mount of over lap if needed.
 

Clint

Well Known Member
#14
It's not lift that's the problem,it's overlap.The maximum duration on these 348 engines is 220 @.050 when they're equipped with the base 9.5-1 compression ratios.You'll need to change valve springs as well,but your stock rocker arms and push rods will work.I can figure the mount of over lap if needed.
I have 0950 cam in my 348.. Cam card says.526 exhaust lift. My push rods did not like the stiffer springs had to go with c
Hardened push rods.
 

Don Jacks

Well Seasoned Member
Supporting Member 3
#15
Cr on the trucks was 7.75-1 but the clearance issues will remain the same.I suggest securing another block,this time form a car.The reason is because the 58 thru 61 model year truck engines use a "double notch" block that makes it difficult to make decent compression.A fellow member built one of these double notch blocks for a cruise around engine.After carefully machining and measuring,making sure that it had a decent quench ,hiis 10-5-1 rated at 10.5-1 netted an actual compression ratio of 8.9-1.On this engine of your,an 0950 cam,an Edelbrock single 4bbl.intake or a tri power set up,and a set of small tube headers is as far as I would go.
 

Don Jacks

Well Seasoned Member
Supporting Member 3
#17
Yep,it's a double notcher.Make a good platform for a boosted engine,the heads are anchors for your fishing boat.
 

Don Jacks

Well Seasoned Member
Supporting Member 3
#19
Those 333 heads have,with porting and bigger valves have been proven to support 500 hp,NA in a stock stroke 09.I can't say the same for a double notcher.With 333 heads,and a dn block,you might be making 7-1.:dunno2
 
#20
I don't see the notch second notch. The Pic was not taken by me. So I have not been in it. I have a buddy with a scope camera might try and borrow to verify. I know the motor is supposed to be 1962.
 
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