Hey guys, hello and great to be here. Anybody got a really really good running 340 6 pack car?? I have a 67 Barracuda that I'm restoring with a 4 speed and 8 3/4 3.91 posi rear. Bought a 69 340 for it. Has had the stock forged crank turned .010 on rods and mains, has stock x heads, .030 10:1 pistons, and I bought a 6 pack set up for it. Pretty well set except for the cam. I want a strong street/strip set up so the right cam is imperative. Of course I want the best of both worlds streetability and big power. It has to whip my son's 1980 z28 Camaro (he has run 13.00 and 106 mph at the strip). Talked to the Comp Cams tech and he recommended an xtreme energy 274/286 duration .488/.491 lift cam. Seems a little small for that induction set up. Or is he being conservative because of the street issuses with a big cam? Any ideas???? Thanks, Woody

If your going to run a cam that is that big you better think about a 4bbl instead of the 6 pack.
You need vacuum to operate the end carb properly.
Im running a 340-6 in my 81 shorty with a OD833 and 3.91s.
I have 268/272/.450/.455 MP Purple cam and performes real well with the ^ pack..

I have help tune and owned a bunch of six pak motors with larger cams than that I'm a comp Cams dealer also, PM me if you want a good deal on a new cam and lifters I would use the XR292HR-10 in your car or a similar grind if you want a stock type hydraulic lifters and cam BTW, you will neeed adjustable rockers and the proper pushrods with the bigger cams like those My street Duster has a Comp Cams custom grind solid roller that is 260 degrees at .050 with .700 net lift, the motor is a pum gas 518 C.I. low deck stroker with a six pak, it has ran 10.43 ET at 128.+ MPH on pump gas with the air cleaner and mufflers on Mopar sixpaks rule, BB or SB

Thanks for the food fellas. Yeah, I know those x heads are old school. Never ported anything before but I'm not afraid. Saw an article in Mopar Muscle where they put a comp xtreme energy 268 cam in a 340 with stock x heads, air gap intake, 800 carb and 1 5/8 tube headers and made 392 hp. Not bad with 40 year old stock heads. A little porting and the 6 pack she should go 425 hp or so I would guess.

Last 340 6 pack I built used a 275hl comp with ebrocks. I was more concerned about power than the cust was,, but he came out very happy.
(still couldn't convince him to dump the six pack )

hi
old schol here , i would use eather the mopar 280-474 hyd or the mopar 284-528 solid !

eather cam should put your car in the 12 sec range !

go with a roller or hydraulic roller camshaft.

plenty of new profiles out there that have nice driving manners and great performance. Solid or hydro...

Welcome to Moparts, Woody!

You've come to the right place to get your 340 dialed in.

Feel free to post a pic of your car and your son's Z28.

I built a 340 six pack a year ago. However, I used a 1199$ 4" stroker kit. It had a comp cams 285XE cam and was externally completely stock. Made 410 hp through the stock manifolds and exhaust, and 440 hp with 1 5/8 primary headers. Should have run 13's without any effort.