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Trying to get help on what cam to use

Old 07-24-2015, 03:05 AM
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Hi I'm trying to decide what cam to get for an 83 k5 blazer was a diesel but put a 350 in it and trying to tune up.going to be a cruiser so not trying to do to much...the truck has
486 gears
Lockers all around
Aftermarket exhaust
Edelbrock carb
Edelbrock intake
Stock headers
700r4 tranny

And should I go with plain hydraulic lifters or get hydraulic roller lifters...and get roller rockers,or just go with rollertips??any help would b much appreciated...
Old 10-10-2015, 08:47 AM
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I've been investigating pretty much the same thing just for the V6 on my 94 Blazer S10.

Please give us a bit more also on the 350. What exact engine, heads, year, scrap yard or crate, mileage, issues?

For info:
The V6 engine is a derivative of the V8 and since the tech stuff is generic in "what to do" this is what I have come up with.

Defining the environment:
I assume that you have the expertise to handle the engine or you have access to somebody and a shop which can do that as you said you have swapped out the diesel for the 350. So I guess you know your stuff.

First let's define what the outcome should be:

Daily driver
Able to pull a trailer
Should not kill the tranny
Should not go heavy on gas

Additional thoughts:
As I'm (and it that case YOU) are going to throw money at it, I (and possible you as well, will want it to last and to get as good mpg as possible with that mod.

First considerations and preparation:
How good is the block?
Will it last or will it develop other issues once you cam it and have the heads done? (Super high mileage - ****ty servicing - noises which are already present - other issues with temperature - issues with oil pressure - issues with oil temperature?)
This should be the basics before attempting any upgrade from top down. If the base is good I would do the following.

Measure compression carefully on every cylinder (I assume that all readings are recorded for later use)
Now go and talk to your machine shop and tell them exactly what you plan is even before touching it further.
They have tons of experience and can point you to the correct stuff. It may need the encouraging words that you will spend bucks on the heads and that their expertise and kindness will maybe influence where you bring your heads...

Later you will have to take it apart anyway to get correct material for the build.
You may or may not pull the heads.
Once you have pulled the heads you will know for sure what stuff will fit and what the condition of the heads is.

What I would build:
I would go with:

hydraulic roller lifters (This will influence the available choice of cams)
a mild cam which fits within the capabilities of your intake (no use to put a hell of a cam into it if the intake/carb cannot deliver - obviously a roller cam).
roller rockers - careful with the lift ratio as now we are talking about issues which can cause serious damage. This is the reason for the question about where the 350 came from. Most probably to get the optimum selection here you have to pull the heads to be able to measure it with the new stuff installed and torqued (or a rocker with the same lift to avoid sending back stuff) and to determine the new lifter lenghts.

The cam should also match your carb, else you will have trouble getting it to run right and have to throw more money at it.
Have the heads checked (you already have the compression at that time and now you can check seats, valves, springs, heads for cracks, intake and exhaust channels, gaskets and you have a very good idea what the block looks like on the oil and on the water side.
When you pull the heads I would at least give all channels a basic grind and gasket/intake/header matching.

Hope that helps for starters.

Anybody else with experience and good ideas?
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