K20 454 truck engine build

[calvinthompson]

I’m currently rebuilding a 85 k20, I pulled a 454 out of an 80s motor home, it had 42,000 miles and the motor is in pretty good shape. I’m going to replace bearings and seals as well as have the machine shop check everything over. I’m wonder what a good cam would be to wake this engine up a little. I’ve got an edelbrock performer 2-0 dual plane and some hooker competition headers I found for dirt cheap at a junkyard, I also found a Holley double pumper 650 cfm with mechanical secondaries I found laying around. I’d like to do some road trips as well as camping and some off-roading. I’ve got a 4” lift and 35” tires. The engine is will be mounted to a sm465 transmission and np205 t-case

 

[DoubleDingo]

Shoot, I would just replace the seals, change the oil, run some MMO in the new oil for a couple hundred miles, change it again, and run it. I highly doubt there is any damage internally. Unless you know it's damaged, or have money to throw away, just run it after replacing the seals.

 

[calvinthompson]

Shoot, I would just replace the seals, change the oil, run some MMO in the new oil for a couple hundred miles, change it again, and run it. I highly doubt there is any damage internally. Unless you know it's damaged, or have money to throw away, just run it after replacing the seals.

I tore the motor apart and the bearings look okay, to be frank, I like rebuilding engines and knowing that they will be reliable. It’s also a lot of fun for me to refresh something so I plan on doing a good refresh. Just looking for advice on a good cam

 

[DoubleDingo]

I'll let the experts chime in on a cam.

 

[MidneightReider]

I vote 540/540 Lunati. Great balance of power and manners.

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[Ricko1966]

IMHO I'd run a Comp 268h it has an operating range that comes in a bunch lower which is where you really need it without trading much off the top. It's what I'm putting in mine.

 

[Ricko1966]

Looking what I found, this would be greatvtruck motor imho

 

[Rusty Nail]

I run a Comp Cams 268H in a 408 and it is completely adequate (for a daily driven street truck) under a Holley 670SA.

Good luck!

 

[SquareRoot]

Gas mileage gonna suck....but hey

 

[85K304SPD]

Don't "over cam" it. You will be happier in the long run with something on the "smaller" side than something real long on duration.
Melling MTC 6 (good old fashioned RV cam) looks good for a 4 x 4. The "268" advertised duration cams would be the "biggest" that I would use.
Off idle grunt, up to about 4000 rpm, is what you really need. If you get into over about .500 lift you will need to make sure you dont get into coil bind on your valve springs. A little bit better gas mileage is another advantage with keeping it on the smaller side. I am running a .456/.476, 204/[email protected] cam in my 410 Big block and it gets about 10 mpg if you take it easy around town. Mash the skinny pedal and it will suck down the fuel quickly, but it responds instantly and runs up to about 4500.

 

[fast 99]

Double pumper will hurt millage, not that it will be that good in any case. Take a look at air flow charts for the CI and operating RPM. Engines require a lot less carb than most people install on them. Others will disagree, my first choice would be a Q jet.

 

[Confused]

For that low compression something like the old rv cam (comp 260H) would work well.Or something similar. Idle to to 4500 where you want all the torque you can get.