Warranty 72 340 built

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oldpunko77

oldpunko77

72 Dusta
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Plan to built this 340 for my 72 question is there several option of piston which I like to stay under 10 to 1 such as 9.6 to 1 what head gasket thickness and plan to use 68 4 speed cam and 3.55 sure grip drop in 72 340 4 speed duster any idea I like to see your input thrown in.
 
Tonight's the night
That we got the truck
We're going downtown
Gonna beat up drunks
Your turn to drive I'll bring the beer
It's the late late shift to one to fear
 
Just build a stock spec 340. You will be happy. Don't over think it. Adjust timing as needed. The recipe was correct when they were built year ago.
 
You won't have 10:1 even if you build it stock. They always blueprinted low.
 
Nice old school 340 manual cam build. You'll be pleased with this one! 65'
 
Is your 340 crankshaft cast (external balanced) or forged (internal balanced)? Do you have the appropriate balancer & flywheel already?
 
Speed pro 2316f will give you about 9.7 with a .028 gasket. That piston is a stock replacement for 68 to 71 340.
 
I wonder if there are lighter pistons and I beam rods are advantage to use?
 
Lighter is better as long as you don't sacrifice strength. Basically, it will rev/accellerate faster. In some cases you can eliminate most or all of the external balance on cast crank 340's & 360's by using the right parts but it's not cheap. If you have a choice between lighter pistons or lighter rods, lighter pistons are the way to go. Weight reduction benefits will be better the further away you are from the crank. You don't want a lighter, weaker rod while keeping a heavier piston especially in higher performance & higher RPM applications.

SRP and Probe are some of the lightest off-the-shelf pistons.

Eagle & Scat I-beam are a good bit lighter than OEM rods but Scat are stronger because they are made from 4340 steel as opposed to the Eagle I-beam 5140.

Cheapest option in a mild application would be OEM 273 rods with good, aftermarket bolts. But the rods would still be over 50 years old and lighter pistons would be recommended IMO.
 
Yes I thought so now I know what to choose to do built this 340 that I have but I am not going crazy with it I remain use oem stock steel 340 crank.
 
oldpunko77 said:
Yes I thought so now I know what to choose to do built this 340 that I have but I am not going crazy with it I remain use oem stock steel 340 crank.
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Then buy a decent rod for it. By the time you rebuild a stock rod you’ll have as much in them as a decent aftermarket rod.

Dont get caught up in the weight nonsense. Unless you run the engine to 8k plus Bob weight isn’t a big deal.
 
True no plans to run up that high most likely 6500 max but once a while on track but mostly on street driven and go hang out event stuff like that.
 
True of course just extra insurance update withe new rods little more money no biggie for me.
 
Don't worry about the weight thing for that mild build. My 340 has stock rods with arp bolts, steel factory crank, and the speed pro 2316s. Seen 7000 rpm for years.
 
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