340 build

[72B5blue]

anyone know of any links to a good 340 build guide? or feel free to give any advice...    Its in a car we are slowly slowly restoring...   The motors coming out this spring.  Its a #s matching 72 challenger rallye car so I want everything to look stock outside.... stock intake, valve covers, thermoquad.. manifolds..Its a forged crank motor 4 speed car.  I'd like to raise the compression to that of about a 70 or 71 340.. maybe a mild cam (any advice on lift duration?),  maybe work on the heads a little... 

any advice? 

Thanks
Neil 

[HP2]

What's your budget and performance goals?

On the high side, you could stroke and poke it to 440 inches, use some W heads, extrude hone the manifolds, go with a full roller set up and optimize quench and compression and make around 600-700 horses for around $20,000.

On the other end, just a good solid rebuild with a balanced lower end, some quench pistons, and some ported heads could be put together for around $6000 and net you around 400 horses.

In either case, do lots of research or work with an engine builder who knows how to build cylinder pressure. Simply buying a 9:1 or 10:1 piston and slapping it in a bore doesn't make the most power. Getting the proper head/piston clearence to optimize squish and matching this to the intake valve closing event on the camshaft is how you will make the most power for the gasoline you want to use at the elevations you run your car.

[Chryco Psycho]

What I have used that works well is the Speed Pro 340 piston & the 308 swirl head from the 87-92 trucks , with some mild porting
Cam choice depends on if you want a solid or hyd grind , I have used a lot of the Engle hyd cams & the Mopar .528 lift solid or the UltraDyne solid grinds with great results as well

[moper]

For a milder street engine, I'd use KB flat tops, redo your heads to modern specs (2.02/1.60 valves, unleaded seat inserts) and stick a modern cam grind in it. It wont cost that much and HP can be boosted 30-40% with no adverse affect to drivability or stock looks.

[Dustu]

One of the best low buck very mild combo I had yrs. ago was a .60 over 340 ,2.02 valves ,750 thermo.,stock int.268adv. dur. .454 lift Comp cam high energy cam ,headers,low comp. {I suppose never checked  back then} .It was a great running eng. street and strip in a 3700 lb car .with air ,727,3.23 posi. got decent mileage,my daliy driver. Lots of high tech stuff out there now but that was my favorite combo worked great for a mild street eng.  9.11 in the 1/8 mi. street tires ,mufflers.Would have been well in the 8's in a lighter car! Wish I had one right now ! Was in a 76' Volare Road Runner they are heavy! It was a sleeper in it's day ,mid 80's .                           On and On .