1995 K2500 350 full performace rebuild

[Ekays]

Hi, I've been planning this rebuild for a while now and I'd like a second set of eyes to go over my parts list. I've rebuilt dirt bikes before but this will be my first performace rebuild on a 350 so I'm sure there's some things I need to know.

I have a 1995 K2500 350, with a 5spd (NV4500) and 14 bolt rear end. 150,000 miles on the truck. Its going to be my daily so it needs to have a fairly flat torque curve. I'd like to make 380 ish hp. I don't tow regularly.

So far my list is this:

Comp Cams Xtreme Energy Hydraulic flat tappet (#CL12-249-4) cam and lifter kit (Lift: .434" /.444" Duration: 249°/260° RPM Range: 1000-5000)

Jegs aluminum heads 195cc intake, 64cc chamber (#555-514063)

Speedmaster Aluminum Roller Rocker, 1.6 Ratio (#746-PCE261100801)

ARP bolts and studs kit

Holley sniper II with full fuel system

Single plain intake (tbd)

Rebuild kit from summit (#SUM-SBCKIT3-311)

Shorty headers (tbd)

3in dual exhaust with X pipe and 2 straight through magnaflow mufflers

Looking at electric water pumps and high output oil pumps aswell (recommendations are appreciated)

From what I can gather this should get me in my desired hp/tq range and run fairly reliability.

Questions:
1. Is the rebuild kit going to fit my stock block and rotating assembly? It says it's meant for pre 86 350s but I cannot find a good complete kit for 90s 350s.

2. Am I going to make the kind of power I want?

3. Will I make this power reliably

4. Assuming I tear my block down and there is not extreme wear, should I still get it decked and honed? I would like to avoid this if possible because I'm already planning on spending alot of money ($5200 give or take after tax). If its something I cannot avoid then how much will it cost me?

Any input is appreciated

Thanks

 

[Sean Buick 76]

Hi, a few thoughts.

1. Before ordering any parts always have the machine shop clean, magniflux and check the block for taper and bore on the blocks bore. At very least get the block honed but the machine shop will tell
YOU want it needs whether bore or hone. Also check the mains for alignment and hone or bore as needed. The deck should be checked to make sure they are both even on both sides and also perpendicular to the mains. Rarely are the decks square and even.

2. Same for the crank the machine shop will tell you if it can be polished or if it needs a cut on the main and rod journals.

2. Once you get your rods and pistons purchased you can mock it up the check quench zone. Mill the decks accordingly to optimize the piston to deck depth. Or do the math and mill ahead of time but the above method is more foolproof.

3. Only once the block machine work is completed can you add the bearings and use a dial indicator to find the inside diameter, subtract the desired bearing clearance so the crank pins can be ground to spec.

3. The cam is a bit smaller than I would pick but it’s better to go smaller than too big. I do think your torque will be good but the Hp may be lower unless you up the cam a bit and optimize the quench distance.

4. Long tube headers for sure, don’t waste time with shortys.

 

[Orpedcrow]

You’re going to have a few hundred dollars in gaskets, sealants and fluids along with other miscellaneous nickel and dime stuff.

I feel like having a balanced rotating assembly is worth doing but not entirely necessary.

 

[Sean Buick 76]

You’re going to have a few hundred dollars in gaskets, sealants and fluids along with other miscellaneous nickel and dime stuff.

I feel like having a balanced rotating assembly is worth doing but not entirely necessary.

I can’t see using performance heads etc without balancing.

I would start with building a solid foundation of the block and rotating assembly and then budget for the heads etc.

 

[Ekays]

I can’t see using performance heads etc without balancing.

I would start with building a solid foundation of the block and rotating assembly and then budget for the heads etc.

Would you suggest a brand new rotating assembly kit? If I went that route could I get away with not going to forged crank/pistons?

 

[Sean Buick 76]

If not revving over 6000 and not using a turbo or supercharger then there isn’t much need for forged parts. A stock crank machined is fine, along with rods, no need to get fancy for a 350 Hp build. A longer aftermarket rod can be found for not much more than the cost of resizing the stock rods and it allows a lighter shorter piston. There are some pretty affordable master rebuild kits that come with everything needed except machine work obviously. I’ve bought lots of master rebuild kits from Northern Auto Parts for mild builds.

For a serious build 400+ Hp I invest in nice forged rods and Diamond pistons etc. but it’s a waste of $ for 350 Hp.

 

[Ekays]

If not revving over 6000 and not using a turbo or supercharger then there isn’t much need for forged parts. A stock crank machined is fine, along with rods, no need to get fancy for a 350 Hp build. A longer aftermarket rod can be found for not much more than the cost of resizing the stock rods and it allows a lighter shorter piston. There are some pretty affordable master rebuild kits that come with everything needed except machine work obviously. I’ve bought lots of master rebuild kits from Northern Auto Parts for mild builds.

For a serious build 400+ Hp I invest in nice forged rods and Diamond pistons etc. but it’s a waste of $ for 350 Hp.

I'm going for high 300s (380?) So it sounds like a forged bottom end would'nt be extremely necessary. Especially since I don't plan to rev above 5000-5500 rpm.

When I was looking at rotating assemblies on summit, I was seeing alot of 383 kits for $600-800. Cast steel and aluminum (not forged). Would it be that much more exspensive to get a 383 kit, have the block machined to a 383, and start with a solid bottom end that way? Would it make sense to go that route for a solid bottom end and spend less on top end? If it's not much more $ than staying with a 350 (because it sounds like i should replace and machine most of the bottom end anyway) I might go that route.

 

[CumminsFever]

You won't regret the step into a 383.

 

[Sean Buick 76]

Yes if money allows look at a 383 assembly and no need for forged rods or pistons at 400 Hp

 

[PlayingWithTBI]

You won't regret the step into a 383.

Yes if money allows look at a 383 assembly and no need for forged rods or pistons at 400 Hp

^^^These...
It's funny, I just took my 88 today with this Blue Print short block, my own heads and running TBI still. I was having so much fun smoking my one wheel peel 275R/60 tires at part throttle

After rebuilding/modifying 2 350s with flat tappet and roller cams I'll never go back - it's just too much fun but, I'll need to get a locker or some kind of posi for it - maybe even wider tires too

One thing I know - I'll NEVER RUN A FLAT TAPPET cam again!

GM SB Compatible 383 c.i. Engine - 436 HP - Short Block Plus

Description: HP & Torque: 436 HP / 443 FT LBS Compression Ratio: 10.0:1 Hypereutectic Pistons Cast Steel Crank Block: 4 Bolt main 4.00" bore Passenger side dipstick Align honed main bearing bore Cylinders honed on computer controlled machine to within .0002 straightness and roundness Cylinders...

blueprintengines.com

They have long blocks on this site too...