340 engine package

[coro500net]

I have a 72 340 that has been built to stock specs(8.5 comp,small valve head,cast crank).This engine has been sitting for 10 yrs, so now I would like
to turn it into a powerful street engine and an occasional drag car.I am thinking of getting a Scat rotating assembly with 10 or 11 comp.Just wondering if anybody has any input on a good way to go on this project?
What will be a good cam,heads,pistons,comp ratio,crank,ect.

THANKS!!

 

[Burntorange70]

There are a lot of ways you could go. What is the rest of your cars combo? Gears,tranny,suspention,ect. What kind of buget do you have? What kind of performance are you looking for. Do you have any 1/4 mile et or hp numbers in mind?

 

[djwhog]

Figure your budget 1st, then figure trans, driveshat rear end gears suspension etc.

You could even do a stroker kit too for a lot of power and keep the thing under 6000 rpm with a lot of power and run 11s easy or low 12s. but you need to decide on the budget 1st.

For not much more you can do a 10:1 416 stroker if not to radical 3.55 or 3.91 gears and a mild convertor or is this a stick car?

 

[coro500net]

My budget will be about 4k.I will be running a 904 with a 411 gear.I will be using stock ft suspension with ss springs.I have my show car, now I want my
go car

 

[3404spdvaliant]

I'm guessing when you talk scat crank kit your saving your stock rotating assembly for a stock app OR you wanna go stroker.

If stock stroke and on a budget as in not looking to spend $500+on pistons then look at the 10.5 KB hypers.

For a cam what do you prefer hydrolick or solid?
If hydrolick then how about the comp XE274 .488-.491 274*-286*dur 110cl
If solid how about the MP.528 284* 112cl [broad pwr band-idle friendly]
Or something more modern like comp XS274 .502-.511 274*-280* 110CL.
what trans are you running ?
Converter=2500 stall would be nice for the street.
Intakes like RPM,LD340,AIRGAP,STEALTH will work.

650-750CFM CARB depending upon stick or auto would be good.

Don't bother with high volume oil pumps unless you altered the oiling system they eat up power, BUT do get a good baffled oil pan.

Heads that flow around 240cfm would be nice=ported iron or eddys, if eddys get the compression to the high side of 10.5 like 10.8
Get headers and a 2 1/2 if if consr=ervative with the gears- 3' exhaust if you have the gears and tires to hook and or a converter that puts you in the power band of your cam/engine combo.
See back pressure picks up the torque below your power band and is good for street, but racers ,for instance, skip the small exhaust and go open headers cause see they don't plan on racing their engine below it's power band.
Gears in the 3.73-4.10 would be best for the cams listed.

After these basic parts it's all about tuning.

 

[rumblefish360]

After these basic parts it's all about tuning.

Aint that the truth.

On a 340, I'd look to a zero deck piston or a slight dome. I figure you'll want to run pump gas and the overall ratio should reflect that. 10 - 1 iron head, 11-1 aluminum head max!

A cam in the area of 240 duration @ .050 will get you going. An example of such cams are;

Comp Hyd. XE284 or the XE285HL for very well ported heads.

Or a pair of solid cams from Comp; 294s (Single pattern cam) or the extreme 282 (Split pattern)

A street strip daul plane intake with a 750 - 800 and 1-7/8 headers with 3 inch exhaust. 3500 converter or so. Converter depends on car weight and such.