7.4L Cam shaft options

[cheerdude63]

Hello all, I have been kicking around the possibility of doing a cam swap in m 97 7.4L. I was looking at the Gen 6 454 XR258HR from comp. I was wondering if anyone had some advice for me on this. Also, has anyone used the EFI connection COP conversion on a gen 6 BBC and left the factory FI system in place?

 

[cool_as_crap]

That looks like a small block cam that wouldn't fit in a 7.4l.
I have this one, an RV cam made for towing:
https://www.summitracing.com/parts/cca-01-412-8

You'd need upgraded springs and a tune to take advantage of any more power from the cam.

 

[Christian Steffen]

Hello all, I have been kicking around the possibility of doing a cam swap in m 97 7.4L. I was looking at the Gen 6 454 XR258HR from comp. I was wondering if anyone had some advice for me on this. Also, has anyone used the EFI connection COP conversion on a gen 6 BBC and left the factory FI system in place?

Though I haven't read into it personally, if you're 0411 swapping there should be no reason you can't convert to COP (CNP) if you want.

 

[cheerdude63]

That looks like a small block cam that wouldn't fit in a 7.4l.
I have this one, an RV cam made for towing:
https://www.summitracing.com/parts/cca-01-412-8

You'd need upgraded springs and a tune to take advantage of any more power from the cam.

I would totally upgrade the springs too. Are you happy with that cam choice, was the difference in power noticeable? What about your economy, did it increase, go down, or stay the same?

 

[cool_as_crap]

I would totally upgrade the springs too. Are you happy with that cam choice, was the difference in power noticeable? What about your economy, did it increase, go down, or stay the same?

So far I am happy it idles like stock and allows me to pass smog.
I only replaced the cam because I had to rebuild my engine and had some lifters destroyed.

I can't honestly tell the difference for several reasons:
- I didn't have much info on the truck nor drive it very much before I had to rebuild it
- While rebuilding it I didn't drive it for months
- While rebuilding it I moved to a different area, making it impossible to compare my experience driving to the same locations
- The truck is still not tuned for the cam

Unfortunately I didn't do much bench marking of before conditions so I won't be able to see improvements as well, since the cam was changed out of necessity and I figured why not upgrade. I'm hoping for more tq for towing and possibly better mpg.

But based on everyone's opinion of our stock cam, anything aftermarket is an improvement. I've read rumors that our engine was de-tuned and de-cammed to help push people toward the 8.1 when it came out, who knows if it's true or not.

 

[cool_as_crap]

It's a bummer FSC is gone, there was a lot of info on our stock cam and upgrades on that forum, plus a massive 7.4 vortec generic thread.

 

[BNielsen]

It's a bummer FSC is gone, there was a lot of info on our stock cam and upgrades on that forum, plus a massive 7.4 vortec generic thread.

Yeah, I was pretty ticked off when I went to do a little research and it was all gone. I'm sure someone out there has a ton of stuff saved from it.

Maybe we oughta start our own generic 454 thread on here?

 

[Christian Steffen]

So far I am happy it idles like stock and allows me to pass smog.
I only replaced the cam because I had to rebuild my engine and had some lifters destroyed.

I can't honestly tell the difference for several reasons:
- I didn't have much info on the truck nor drive it very much before I had to rebuild it
- While rebuilding it I didn't drive it for months
- While rebuilding it I moved to a different area, making it impossible to compare my experience driving to the same locations
- The truck is still not tuned for the cam

Unfortunately I didn't do much bench marking of before conditions so I won't be able to see improvements as well, since the cam was changed out of necessity and I figured why not upgrade. I'm hoping for more tq for towing and possibly better mpg.

But based on everyone's opinion of our stock cam, anything aftermarket is an improvement. I've read rumors that our engine was de-tuned and de-cammed to help push people toward the 8.1 when it came out, who knows if it's true or not.

Stock tune sucks, so you'll definitely notice a difference once you tune it.

I really wish I had the time and resources to hit up a Dyno with a couple different 454 trucks and see how different cam options play out.

The closest comparison I have is a stock truck I tuned vs a 461 (.030 bore?) Truck with the same cam I have that I tuned. The one with the cam felt a pretty good deal stronger and it was in a cclb vs ccsb with the stock cam.

The stock cam truck did have 130k on it though vs the replaced cam being a rebuild and it had headers. Really this isn't a great comparison but it's all I have aside from my own truck.

What route were you thinking about going for a tune? If you're going to use someone that'll retune multiple times it would be really interesting to have it tune, then swap cams and retune.

 

[Supercharged111]

I didn't know FSC kicked the bucket, must be recent. That cam above is damn near identical to mine, 212/218 .518"/.527" 114+2. Drives like stock with no VE or MAF changes. Mine has a little valvetrain noise, how about yours crap? I did install the Comp adjustable valvetrain sleeves and studs. Really should get around to measuring and swapping in the correct length pushrods.

 

[cheerdude63]

Supercharged111, how did that cam do compared to a stock cam, any economy improvements, noticeable power increase?