340 build up

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GDL

GDL

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Ok, so I am picking up a '73 340 and I already have some '69-'70 340 heads. It's supposedly a virgin block.......

So assuming that the block specs out, does anyone have a recipe for a decent build? I'm not looking for an ungodly build that will shatter records nor am I looking for a stock build where the original cam is used kind of thing.

Anybody have any ideas?

I'm assuming I'll need new pistons and rods.
 
.030 over trws, resized rods with arp bolts, j heads with 2.02 valves, eddy rpm cam, air gap, headers, 750 cfm carb, wents 12.90s at 106 in a 3650 lb duster with 3.91s, a 2800 converter in a 727 with a slow 1.88 60ft, not the best build ever but knocked out 17 mpgs on the highway on pump gas.
 
Basic high compression rebuild (L2316 or KB243 series pistons). Heads rebuilt with 2.02 intake valves and basic porting. Comp XE274 cam. Performer RPM intake. 750 CFM carb. Headers and 2 1/2" dual exhaust. Best torque converter you can afford. BALANCE.

Your rods can be reused, but there are new sets out there for not a lot more than having the originals reconditioned.
 
I can give you the specs of my 340 build if you want. My is also a 73 block but I converted it over to internal balance.
 
For certain! Balance it internally.

Now about your build. Answer these questions please as to narrow down an idea as to what you may do.

What is your gear ratio and tire size? (What you'll end up with actually)
Will you change the converter out for a higher stall?
Will you use headers?
 
the only thing i might add to that article is pocket porting or upgrade to EQ/RHS/EDDY heads
 
273 said:
the only thing i might add to that article is pocket porting or upgrade to EQ/RHS/EDDY heads
Click to expand...

The heads will get a super mild job just to clean up the crud that's accrued over the years.

They arent beauty pageant heads by a long shot.
 
Mild porting, kb hyper pistons dialed compression to 9.5:1, mp.528 cam advanced 5, 273 rockers and push rods, LD340 intake with cross over blocked, Holley type dbl pumped carb of 800 cfm , headers, elec ign with 24* intiail and 32* full adv all in by 2200rpm , 3.73-3.91 gears at/mt 'with auto 2800 stall'
 
1wild&crazyguy said:
Mild porting, kb hyper pistons dialed compression to 9.5:1, mp.528 cam advanced 5, 273 rockers and push rods, LD340 intake with cross over blocked, Holley type dbl pumped carb of 800 cfm , headers, elec ign with 24* intiail and 32* full adv all in by 2200rpm , 3.73-3.91 gears at/mt 'with auto 2800 stall'
Click to expand...

^^^^^ That's a strong runner.

You aren't getting 390hp from that magazine build!
 
My suggestion is just know what you want before you start, it gets rather expensive if you change "gears" in the middle. Best of luck.
 
340RULES said:
My suggestion is just know what you want before you start, it gets rather expensive if you change "gears" in the middle. Best of luck.
Click to expand...
yes you should determine what your gears will be and go from there .
 
And that's why I'm asking for input. I get to pick the block up tomorrow.
 
What HP do you want?

That's the question you need to answer.

Gearing and converter can come after that.
 
Before I invested a dime in cast iron stock heads....especially if you need to install larger valves , I'd look at Eddies , RHS X heads ( these are iron ) , Airwolfs or similar.
By the time you hot tank , surface , port , do guides ( it will probably need them ) , valves , springs and a good valve job..........let's hope the seats are all good and there are hardened exhaust seats or you can add another good chunk of dough.
Yep......add all that stuff up.
Better mag those castings too.
I am not trying to discourage you. Just prepare you.
Wit aluminum heads , you can run a little more compression too.
With Eddies , 10 to 10.5 : 1 , cam in the .500 ish and 235 @ .050 numbers.
Air gap and 750 to 850 d.p. 1 3/4 " primary headers. Good converter.
Stab it and steer.
My 340 was milder than that cam wise , with an M-1 and 750 d.p. , 1 5/8th primary headers ( it was an early A and these came with it ) , loose converter of unknown heritage and a 3.91 cog. Ton of fun on the strasse and quick enough to maintain respectability. I whooped up on a buddy's '65 Vette with a 327 / 350 h.p. stick shift car severely , so I guess it was kind of quick. No idea of the weight , but it was full interior and frames tied , 7/8th offset spring hangars and SS leafs. Nothing fancy.
Like others have said , be SURE what you want and expect.
Then do it once.
 
Oh when pulling it tomorrow since its a '73 I definitely need the flex plate but what about the converter?
 
Internally balance the motor. You can get a scat I beam kit for a decent price. Personally I'd get the setup in forged for future growth. Something to thing about.
 
crackedback said:
What HP do you want?

That's the question you need to answer.

Gearing and converter can come after that.
Click to expand...

I agree thats the proper way especially when doing a race car, but most people seem to run 3.23-3.55 gears no matter what, so If that's all the gear your gonna run with, pick parts that's gonna give you more under 4000 rpm since that's where you engine gonna spend most of its time. But also when selecting parts try extend the powerband to the point if went any more you would start give up bottom end for top end, because there no point pick a cam that's gonna give you 30hp extra at 6000 rpm and sacrifice 30lb-ft down low if car rarely see's 6000 and if you need more power then that, go with a bigger engine.
 
Well after a long drive that lasted from 7 AM to almost 6 PM. I am proud to say my buddy and I were successful. (most pics have my buddy in them). On the plus side the intake was free.

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Anyone have a '73 727 TF flex plate for me? The guy didn't have it.
 
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