Magnum rods and KB167 pistons?

[Mojoe9955]

I have a stock 5.2 Magum motor, I wanted to build. It has 195k on it and looks like I can use all the stock parts.
I have a chance to get a deal on this rod and piston combo and am wondering if this works? My original plan was to use the existing stock combo with new bearings, rings and a hone. I have some good bare EQ heads that at the very least were to get "decked" and a 3 angle valve job. The usual dual plane, 4 barrel and headers and an Oregon regrind on my stock cam, using my rockers and lifters for an economical combo for a 72 Demon I have. I have an LA timing cover, 360 oil pan and all the necessary parts for the LA look.
The aforementioned pistons are .30 over so the cylinders would need to be bored. Originally my only machine shop bill would be for the heads, which I thought of having some porting and these heads are for LA intakes so gasket matching might be in order as well.
With this in mind, which gets me most bang for the buck? The KB167's and basic head work or the stock pistons and ported heads? The KB's add extra cubes and compression depending on the head cc's. There certainly benefits to combining both. Most often I start going for economy and end with, "what the hell I might as well "

 

[Garrett Ellison]

I woudn't "deck" the heads any more than necessary to true them up. Magnum deck height is 9.58. If you really want to increase your compression, deck your block to positive deck height so that you get .035-.040 quench distance to the cylinder head with the head gasket of your choice. But, how much gear, converter, and cam are you wanting to run, and are you wanting to run on premium pump?

 

[TT5.9mag]

You’re kinda screwed either way. The stock piston won’t let you take advantage of the ported heads because they will limit the cam you can run. So pistons become necessary with the ported heads. Extra cubes from a 030 overbore is a non issue and shouldnt be considered. If you’re going to build it, build it and make it what you want. If not leave the bottom end alone and “go for economy” as you put it. Either way, start with a goal and do what it takes to get to the goal. Don’t buy parts and change the goal because they were a good deal.

 

[RustyRatRod]

Aren't the rod small ends somehow different from Magnum to LA? Seems I remember something about the width of the small ends being different.

 

[TT5.9mag]

Aren't the rod small ends somehow different from Magnum to LA? Seems I remember something about the width of the small ends being different.

Yes magnum rods are narrower on the small end.

 

[RustyRatRod]

Yes magnum rods are narrower on the small end.

Thanks. I thought I was remembering right.

 

[Mojoe9955]

A used set of pistons and rods are $200. So it was just a thought as I'm planning my build. I don't need the rods and don't hear people here recommending them so I'll research it more and save the money.

 

[Mojoe9955]

I woudn't "deck" the heads any more than necessary to true them up. Magnum deck height is 9.58. If you really want to increase your compression, deck your block to positive deck height so that you get .035-.040 quench distance to the cylinder head with the head gasket of your choice. But, how much gear, converter, and cam are you wanting to run, and are you wanting to run on premium pump?

I agree just enough to "true them up"

 

[Mojoe9955]

Yes magnum rods are narrower on the small end.

Does that make a difference? The pistons are listed for use in 92-03 5.2 Magnums on Summit.

 

[Mojoe9955]

I woudn't "deck" the heads any more than necessary to true them up. Magnum deck height is 9.58. If you really want to increase your compression, deck your block to positive deck height so that you get .035-.040 quench distance to the cylinder head with the head gasket of your choice. But, how much gear, converter, and cam are you wanting to run, and are you wanting to run on premium pump?

No premium, I like the 3.23 w/ Suregrip. I have a 904 with a Tf- 2 shift kit and was thinking a 2200-2400 converter. The only mystery would be the cam grind?

 

[TT5.9mag]

Does that make a difference? The pistons are listed for use in 92-03 5.2 Magnums on Summit.

Nope

 

[JDMopar]

Will the KB 167's work with the EQ Magnum heads? The Magnum heads are closed chamber heads and the KB167 pistons were designed for open chamber 318 heads. You can probably run them if you use a thicker head gasket to get the proper quench.

 

[RustyRatRod]

Will the KB 167's work with the EQ Magnum heads? The Magnum heads are closed chamber heads and the KB167 pistons were designed for open chamber 318 heads. You can probably run them if you use a thicker head gasket to get the proper quench.

There's no reason why they won't. They don't have a dome and they aren't positive deck height.