340 Stock Stroke Street Build Recipie For a 73 B-body

I'm looking to help a buddy who wants to wake up his 1973 340 Charger. Looking for a pump gas engine with a stock stroke and stock iron 915 heads with a good valve job and pocket port, stock exhaust manifolds, with a stock TQ carb and and intake that will work with it. Shooting for stock look but with more power.

I know I'll hear this a lot (I preach it myself) but a stroker is not an option

I would go with the KB243 piston and work hard on getting the quench good. It will be right around 10:1 if I remember and with the quench it will likely not have any problems with pump fuel. I can't help much with the manifolds and carb but getting as much compression as you can on pump fuel doesn't hurt.

I had a stock stroke 340 in my car in high school and modified more as time went on. It had the KB243s with good quench and ran on 93 octane for years with no trouble. Once I had the X heads ported and used a good converter it went 11.98@114 in good air. I want to build that motor again for something else someday, it was fun.

well you already know the stock manifolds will kill a lot of power. all i can add is i run 11.25cr with J heads and speed pro flat tops, the heads have been milled a lot 59cc. 195 cranking psi. runs good on 93 with very cold plugs. a lot of torque and nice pop out of the exhaust!

Extrude Hone the buggery out of those exhaust manifolds? What about stock Eliminator I've got a recipe for all the tricks for a Bob Lambek h/s build I could dig the book out if you want.I think I know where it is it was only 1992😆

How about some cam numbers. Remember, pump gas, heavy car, street driven

Interesting question: you could go with a torque build and give up peak HP, or throw alot of gear and converter in the car and make a high winding HP engine, but with the stock exhaust and intake your really limited the RPM range and HP, so need to focus on torque and high VE in the low to mid RPM range. If you can still get some gear and higher converter stall, you can tighten up cam LSA to help the mid to upper range while still running smaller duration lobes.
I'm thinking something like the Hughes 223/236 Whiplash cam, but 9.5-10:1 compression?

What's the gear ratio and tire size?

Extrude hone maybe 3-4hp for $500 bucks. Not worth it imo. Stock brackets recipe call for stock lift cams running 350* duration & 7000rpm. Not exactly street friendly.

You can only wake up a stock motor so much if most of it is going to remain stock.
Push the cr as high as you dare, little bit of a cam(solid lifters would be worth a little something), mild bowl port on the heads, 2.02 valves.
Not really much else that will fit the rest of the criteria.

For sure, the absolute best way to really enhance the fun factor for that type of project is a stroker. Anything else will be way way less effective.

Is he open at all to aftermarket heads?

Heads like iron W-2's give tremendous gains and kinda disappear after painted and all the accessories are installed.

What gear? Any type of converter? Low gear trans an option?

That is the answer. Take the 340 out and store it for someone that has to have a 340 and is willing to pay stupid money for it. If you want the 340 look, get a 318 core, bore it .030 and fit it with a cast 4" crank and at least 9 to 1 pistons. A mild cam and 4 barrel will run well on today's gas. JMHO

OK, here is my flying blind answer;

Comp cams has a line designed just for exhaust manifolds.
Crane cams for years has been making cams with extra duration.
Larry Shelard has said to use cams like this in unported or mildly ported heads since the exhaust is poorer flowing and could use the help with a longer duration.

Choose the cam with the cruise rom range in mind that fits the driving rom range.

If you are changing the converter, Comp Cams biggest exhaust manifold cam is good to go with and a mild converter.

Scott,

Since the pistons have been discussed, Lets talk camshaft, converter and gear.

How about the good old XE268
18-20 degrees initial timing, 36 total at about 1800RPM and another 15 degrees in the can for cruising

A "tight" 10" converter with at least a 3.73 gear since I'm sure he'll be running something like a 255/60-15 in the back.

Shift @ 6000Rpm

I'd want to know what gear & tire and how he wants to use the car, and whether he wants to spin the motor or not.
For street use, I've had better results with lift than duration.
Obviously a stroker allows a taller gear for highway use. Might even be fairly cost-effective depending on the engine's existing condition and finding a deal somewhere.
All the usual stuff applies, like detailed tuning efforts, better exhaust system, maybe 2400 stall, and/or more gear.
Then there's weight reduction, if that's an option.

Why is a stroker not a option? Thats not going to be a very fast car with exhaust manifolds. even if he spends a ton on ported intake and max 915 heads with 2.05's valves, if CR is pump gas friendly its probably a 350hp motor but in that body a 14 second car in street trim

for a huge car like that increasing the cam or head flow may
be the worst thing you could do.A bit of lift and less duration
would be better.
there is not a lot you can do with a small engine in a huge
car.A gear and a converter will help as well.

268 XE would be very lazy in a big car like that until about 40 or 50 mph.
how about the generic 204 / 214, .429 / .444....good lo end torque.
that should break the tires loose and pull good beyond the speed limits

I never ran a 340 in a B-body but when I was
running stock stroke 340s in A-bodies on the
street I always started at the back of the car..
I started with a gear in back then conv then worked
on the engine... in 340s the valve springs were always
the weak link.. I would change them even if it was the
stock cam so it could rev a bit more

Why ask why ? Just work the issue. You can argue all you want for a stroker. But it is simply just NOT on the option list.

The 268 would be lazy if the stock converter is retained and the rear gear was numerically low.
The cam you posted specs to looks like a actual OE 340 cam. Is this correct?

Scott, I hate to badger, but we need some more info/help on this build.
What is the rear gear & tire size?
Is a converter change an option? Unless it is a manual trans?
Is the engine going into a full rebuild?

Other than the above recomendation I made about the Comp Cam for exhaust manifolds, I normaly run a split duration cam with unported heads with headers or not, with 8*'s more exhaust. Thus helping with the corked breathing.

Iron headed engines with small cams work very well with a 9.0-1 ratio. (In case this is a full on rebuild.)

...stock 340 lift with much less duration,ideal for a heavy vehicle ..nearly every manufacturer sells a similar grind

Had a HP 360 in a 74 RR with a 4-speed. Same basic cam as a 340. Was plenty fast. With the 73 Charger I'd put 1.6:1 rockers on the list. Shave the heads to get as much compression as possible. Pocket port, gasket match. Put a strip kit in that TQ. IF budget allows put more converter & lower gears.

Scott,contact AJ at BGR,he has a 340 engine complete that has 6 pak heads and flat tappet cam,polished single four Mopar intake,polished aluminium valve covers,Roller rockers,deep pan,Fluid Damper and extras.It was in a 3400 lb Cuda,rotating assembly is balanced.We built this engine back in mid 90s and it just has been setting around.It ran consistant low 11s and in good air ran 10.90s.
AJ at BGR 412-216-4727