Cam options

[Erik the Awful]

I do want a more aggressive idle, but more importantly I need more torque at lower rpms to get the truck moving easier, since it has a 4" lift and 33"(?) tires.

I've been doing some research and learned that most likely no matter what I go with, I'll have to replaced the valve springs and advance the timing. Now it's just a matter of finding what sort of duration will work with the TBI heads.

So whats the difference between advertised and actual duration?

I have two kits from Comp cams I've been looking at.
#1 Everything in this kit should work with very little modification.

Xtreme Energy 206/212 Hydraulic Roller K-Kit for OE Roller SBC

Xtreme Energy 206/212 Hydraulic Roller K-Kit for OE Roller SBC stock to mildly modified combinations. Strong torque and good mileage.

www.compcams.com

#2 And this one, I check most of the boxes. I have headers; 3.73 gears; and 2400-ish converter stall. Although this one has a higher rpm range then #1. This one says it requires headers. I do have a pair, but they are intended for my C1500. So how would this affect the performance if I used the stock manifolds? https://www.compcams.com/xtreme-4x4-220-224-hydraulic-roller-k-kit-for-oe-roller-sbc.html

I live in Arkansas; no emissions testing. And the truck does not have catalytic converts(previous owner).

...but did you call Comp Cams and ask their advice, or did you just poke around their website? Call them.

This is the better of the two cams for your application, but I'd call them to be sure there isn't something even better. www.compcams.com/xtreme-energy-206-212-hydraulic-roller-k-kit-for-oe-roller-sbc.html

Advertised duration is a claim with no standard. Duration @ .050" is a standard that everyone uses now. To keep gas mileage and driveability, you want to keep this number down around 220 or less. The factory duration on a TBI engine is 194/202, so if you want a more aggressive cam, aim above that. The cam above's 206/212 is respectable, and the .480/.487 lift is healthy. Put a free-flowing behind it and it'll have the sound you're looking for.

A full grand for a cam kit? Ugh. If you can run stock roller lifters, I would. If the lift were down in the sub-.450" range I'd run new stock springs, but with the .480"+ lift, I'd go with LS2 beehives and Comp's 787-16 retainers.

Call Comp Cams before you order to get a sanity check.

 

[Schurkey]

something within the limitations of the stock head

I grabbed a block out of a 96 pickup.

Studied the difference between TBI blocks and Vortec blocks?

 

[VIKING_MECHANIC]

Studied the difference between TBI blocks and Vortec blocks?

The blocks are the same. Unless you have a TBI block that came with a flat tappet cam. Which in my case it is hydraulic roller.

 

[Erik the Awful]

The blocks are the same.

No, but they're very close. Check that cam retaining plate mounting diameter. Drill the coolant bypass hole.

 

[L31MaxExpress]

No, but they're very close. Check that cam retaining plate mounting diameter. Drill the coolant bypass hole.

May already have the bypass passageways drilled. I have had probably a dozen L31s and only personally seen 2 or 3 that did not. My L30 was drilled as well. Drilling the bypass on a block that does not have one is a complex operation and the head needs to be drilled as well if the Vortec head is being used.

Better to drill a 1/8" hole in the thermostat. The heater core is also a continuous bypass in stock form.

 

[VIKING_MECHANIC]

Both blocks are 880 casting. The one that was in the truck has a 4 bolt main and my salvage block is 2 bolt.

Drill the coolant bypass hole.

Where would I find if this is already drilled or needs to be drilled?

 

[Schurkey]

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A "double drilling", from the deck surface down at an angle, leading to the hole drilled from the front of the block under the right-side water pump opening.

All of this mates to the pre-Vortec water pump.

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...but NOT used on the Vortec blocks. Some Vortec blocks (4-bolt main blocks in my very limited experience) have the holes, but they aren't used.

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And then there's the missing front-cover dowel pins and two non-drilled, non-tapped cover bolt holes.

 

[HotWheelsBurban]

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A "double drilling", from the deck surface down at an angle, leading to the hole drilled from the front of the block under the right-side water pump opening.

All of this mates to the pre-Vortec water pump.

You must be registered for see images attach

...but NOT used on the Vortec blocks. Some Vortec blocks (4-bolt main blocks in my very limited experience) have the holes, but they aren't used.

You must be registered for see images attach

And then there's the missing front-cover dowel pins and two non-drilled, non-tapped cover bolt holes.

And that, kids, is why Chevy water pump gaskets have 3 small holes....

 

[L31MaxExpress]

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A "double drilling", from the deck surface down at an angle, leading to the hole drilled from the front of the block under the right-side water pump opening.

All of this mates to the pre-Vortec water pump.

You must be registered for see images attach

...but NOT used on the Vortec blocks. Some Vortec blocks (4-bolt main blocks in my very limited experience) have the holes, but they aren't used.

You must be registered for see images attach

And then there's the missing front-cover dowel pins and two non-drilled, non-tapped cover bolt holes.

I remember pointing that out to you. Glad you took pictures for posterity to understand the bypass setup.

 

[Schurkey]

I remember pointing that out to you. Glad you took pictures for posterity to understand the bypass setup.

Yup. I screwed the pooch on my truck 'cause I failed to drill the "vertical" hole.

I keep telling myself that when I get enough electricity to run the welder, I'm going to build a drilling fixture for that hole. But getting electricity is proving to be a challenge. Or rather, getting electricity into an enclosed area that protects the shielding gas from being blown-away by the wind, is a challenge. And all my circuit-breaker panels are maxed-out.