Camshaft recommendation for my specific Slanty build?

hellfirechrome said

Howdy! Looking for an experienced recommendation for my build. First, the hardware;

1965 Plymouth Barracuda

Stock reman Slant six 225:
-Cliffy (not Offy!) Hyper-Pak
-Edelbrock 1403 with small jets & fat rods (live at 6200ft so leaned out)
-Stock exhaust manifold
-2.5" mandrel exhaust/glasspack muffler
-No PS or AC
-Electronic ignition (Mopar chrome box)

Driveline:
-904 Automatic Stock
-8 3/4" rear with 2.93/LSD
-4 wheel disc brakes, manual Wilwood style master

I'm looking for a midrange-RPM torque-centric cam, I have a vintage 13' camper trailer I'll be towing on occasion. Driving-wise, I prefer road course style driving power, not really drag/off the line. I plan on keeping the 2.93 for now, might go 3.55/3.73 down the line.

Whose cam & what grind(s?) should I lean toward for my build? What's going to give the most CFM flow improvement with that Hyper-Pak and still be streetable? I don't run Power brakes so a drop in vacuum/lopey idle is fine. I'm hoping someone will be speaking from experience running a Hyper Pak and similar 4bbl on a stock block. I've got NO interest in grinding heads, porting, polishing or anything too involved right now. Cams are an afternoon project, wanna keep it that way :)

Thanks in advance! Here's my baby, she's coming along nicely...

View attachment 1715589032 View attachment 1715589033

Click to expand...

Spent months with Doug Dutra with a simulator and selecting parts for my 225 looking for the exact same thing. I just got mine running last weekend and have not dialed it in for real yet but wow does it run great for a fun grocery getter. It will die off over 4000 RPM but I never drive it there.

Here is what I did.

225 Torque Build is Alive....

for what you want the hyper pack long runners are for a 170 running 7000 RPM on the track. Not useful in a 225 with high gears. For 4000 RPM max builds the key ingredients are

1) up the compression by milling the block.
2) Dutra Duals with the Y connecting them 45” to 50” from the flange any closer and it only helps above 4000 RPM
3) a cam with no more 108 LCA. And short duration. Yes you heard me right. The 268 comp cams are too much duration and you loose a lot under 4000 RPM (but you do gain a lot over) use a Oregon Cam 2106 or a Dutra RV10. Don’t get in the RVP discussion. It really does not matter for under 4000 RPM builds. You just want short duration for street torque. The Dutra RV15 is between these and the Comp cam.
4) don’t go too big on the CFM of the carbs. For 4000 RPM and less engines 400 is all you need and if you can do it in a way that can be progressive so you have less than that at lower RPM the better. You take my build and throw 500 CFM carb on it and it tanks the low end torque for gains at high RPM (if you have the oversized valves to use the more flow)

I did oversized valves as that does help keep the power up at higher RPM with the short duration. Would I do it again? Maybe. I need to get some peddle time on this build to answer that.

Jim.