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I'm looking at the Summit pro LS 8713 cam because it's what they use in their 450hp crate engine. Their crate engine is identical to what I have in my 2002 blazer.
It has a 5.3 LMG 24x 243 heads, flat top pistons, 33 lb injectors, full 2 1/2 exhaust. 4L60E with a 3000 converter, 3.42 rear and 27.5 tires.
I guess with the 8713 cam I'd have basically their crate engine. BUT I'm wondering what kind of hp it's putting out now and if it would be worth the swap. Right now it has their 8719 cam.
What do you do with the vehicle? what kinda driving?
If it were me Id make the cam change a little more worth it and go with something like the 8707 if your valve springs are good enough and since you already have a 3000 stall, but I like my stuff a little more rowdy.
Everything you gain from the 8713 over the 8719 up top would be lost down low, but your stall would push you passed most of the low rpm loss.
I wonder what I'd gain with this swap. I drive it normally but want it to be faster when I get on it.
I did have this same engine in an s10 and put a 8708 cam in it along with a tbss type intake and 92mm tb.
It tuned good and ran strong but wanted to rev to 7200+ to get peak power.
Now I have a 6.0 LFA in the s10 with the 8706 cam. It's a little milder but the power is usable.
With this blazer and the 5.3 I just want it to be faster. If it picked up more power around 3500 to 6500 it would be good. And these two cams require the same springs so I'd only have to change the cam.
I'm just curious what it might be making now power wise since they claim 450hp with the 8713.
And my tuning is perfect right now so I really don't want to retune for a new cam unless there's 50hp to gain or more. With the cam swap.
I also have another tbss intake and 92mm tb to put on it if it'll help. I know as it is now with the 8719 cam it nakes moee power with the stock intake and tb.
check out Richard holdner on YouTube if you haven’t already, search for truck cam test he has done some with similar specs to what you have now and what your looking to swap to.
That answers my question. 25hp gain if I'm lucky. Not worth it.
I'm looking to get away from the 5.3 anyway.
Thanks for the help.
0
The 5.3 is a good engine, imho. But with only the same lift as the OEM LS6 cam, a bit more duration, and a tighter LSA, you can't expect big gains. With those duration figures, all you need is a bit more lift. If it was me, and again, mho, I'd go with .570"-.580" lift, maybe 224°/228° duration on a 113°-114° LSA. You have the 3,000 stall converter. Maybe I'm a bit more aggressive than some, as the other guy posted he was rowdy!!
Last edited by grinder11; Jan 12, 2023 at 10:43 AM.
The way they "cheat" cam power numbers is you test the stock engine, then install the headers with the stock cam and gain a few HP, then replace the cam and it looks like that new cam is the greatest thing ever but it wouldn't have had half the gain without the headers.
Exactly. I don't agree with everything Richard Holdner does or the way he does it. His 100 hp cam only 5.3 is what made me put the 8708 cam in this 5.3 the first time. It was a close cam to the comp cam he used.
He has said why he starts his dyno pulls at 3000 to 3500. Because when are you ever running below that anyway. I guess on a dyno.
So the results of the 100hp cam only 5.3 shined above 5500 iirc to 7500. Below that was just about the same power as stock. So my thought is when am i ever running at 7500.
Then I asked on another forum and everyone said the cam was way wrong for my engine. So why was it so right for Richard Holdener. Because he wows people with dyno numbers. And I know I could analyze his work and figure out how it would work in my application and I should have, but you see that gain and figure you can make it work. Not really.
But I'm starting to think I need more cubic inches to get more power down low no matter what the cam.
I'd like to have a good pull from 2500 to 6500 or higher while keeping the stall speed below 3000.
Exactly. I don't agree with everything Richard Holdner does or the way he does it. His 100 hp cam only 5.3 is what made me put the 8708 cam in this 5.3 the first time. It was a close cam to the comp cam he used.
He has said why he starts his dyno pulls at 3000 to 3500. Because when are you ever running below that anyway. I guess on a dyno.
So the results of the 100hp cam only 5.3 shined above 5500 iirc to 7500. Below that was just about the same power as stock. So my thought is when am i ever running at 7500.
Then I asked on another forum and everyone said the cam was way wrong for my engine. So why was it so right for Richard Holdener. Because he wows people with dyno numbers. And I know I could analyze his work and figure out how it would work in my application and I should have, but you see that gain and figure you can make it work. Not really.
But I'm starting to think I need more cubic inches to get more power down low no matter what the cam.
I'd like to have a good pull from 2500 to 6500 or higher while keeping the stall speed below 3000.
You are correct. Low end power and peak torque is a function of cubic inches. No cam can let your engine burn more fuel in a given rotation.
A 5.3 can be a lot of fun, but it will never make more than maybe 400ft/lb of torque without forced induction.
Two things come to mind:
Most of us do NOT drive a Dyno to work....
and 3.42 axle gears are unsuitable for small engines.
I'd run the 209/217 cam, it should be great manners on the road.
I wonder what I'd gain with this swap. I drive it normally but want it to be faster when I get on it.
I did have this same engine in an s10 and put a 8708 cam in it along with a tbss type intake and 92mm tb.
It tuned good and ran strong but wanted to rev to 7200+ to get peak power.
Now I have a 6.0 LFA in the s10 with the 8706 cam. It's a little milder but the power is usable.
With this blazer and the 5.3 I just want it to be faster. If it picked up more power around 3500 to 6500 it would be good. And these two cams require the same springs so I'd only have to change the cam.
I'm just curious what it might be making now power wise since they claim 450hp with the 8713.
And my tuning is perfect right now so I really don't want to retune for a new cam unless there's 50hp to gain or more. With the cam swap.
I also have another tbss intake and 92mm tb to put on it if it'll help. I know as it is now with the 8719 cam it nakes moee power with the stock intake and tb.
Sounds like you'd be better off just doing the intake swap and changing the rear gears to 4.10s.
Sounds like you'd be better off just doing the intake swap and changing the rear gears to 4.10s.
I had that intake and tb on when I first installed the 8719 cam. I put the old truck intake and 3 bolt tb back on and felt a seat of the pants difference in low end power. More with the old style intake.
I have been thinking of 4.10 gears too.
Maybe the intake would work better with this converter and 4.10's?
I never understood how all the newer trucks come with that intake but it seemed slower for me with this cam.
I'm still looking at junkyard inventory daily. I see a lot of 6.0's and 6.2's but I'd need to take a day off work I guess to get there when the doors open. I've been there 3 hours after they open and everything is gone. I just saw a 2016 L96 listed last weekend and ran the Vin. 750,000 miles it was a prison transport van. Someone beat me to even that one.
Exactly. I don't agree with everything Richard Holdner does or the way he does it. His 100 hp cam only 5.3 is what made me put the 8708 cam in this 5.3 the first time. It was a close cam to the comp cam he used.
He has said why he starts his dyno pulls at 3000 to 3500. Because when are you ever running below that anyway. I guess on a dyno.
So the results of the 100hp cam only 5.3 shined above 5500 iirc to 7500. Below that was just about the same power as stock. So my thought is when am i ever running at 7500.
Then I asked on another forum and everyone said the cam was way wrong for my engine. So why was it so right for Richard Holdener. Because he wows people with dyno numbers. And I know I could analyze his work and figure out how it would work in my application and I should have, but you see that gain and figure you can make it work. Not really.
But I'm starting to think I need more cubic inches to get more power down low no matter what the cam.
I'd like to have a good pull from 2500 to 6500 or higher while keeping the stall speed below 3000.
That is why I have said numerous times over the years, the best cam swap for a 5.3L or 4.8L for towing has a 6.0L or 8.1L block wrapped around it. Then again it might be cheaper to find a Magnuson, Edelbrock or Whipple twin screw. 10 psi of boost will add a ton of torque and power. Nearly 20 years ago I put a Weiand 177 on a TBI 350. It was an intake swap that more than equaled a Vortec 454 of the time. Its an easy formula too, stock engine plus a blower, larger injectors, tuning and add headers to get the exhaust out. At ~10 psi that 5.3L should breathe about 50% better, like it is an ~8L and make the corresponding torque. When you are cruising around at light throttle it runs like a 5.3L, step into the throttle and its like having a larger engine on demand. I think it was Magnuson and thus Edelbrock that claim at 60 mph at part throttle with the bypass valve open the supercharger only takes 1/2 hp to spin thus stock fuel mileage when you are cruising along. With a stock engine and a blower, think of it like having another 50% of your current accelerator pedal. Instead of 0-100% it becomes 0-150%.
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Gains with this cam swap? 
it was a prison transport van. Someone beat me to even that one. 
