ls2 or ls3

[GMC70c20]

I am looking at crate engines for my c10, Iv'e decied I want a aluminum block ls engine. I have found 2 that I like but the price is about $3000 different by the time I by all the ingniton contols. I dont really plan on taking the truck to the strip alot and I dont plan on taking it on long drives. It will be just something fun to cruise around on the street and take to the strip every now and then, it wont get driven in the winter, late fall and early spring and rarely in the rain. In the near future I thought about bring the hp up to about 550hp with a centrifical super charger. I've not really decided on the trans either it will either be a th-350 or a 700r4. I realize that these 2 engine and trans combo's are completely diffrent but let me know what you guys think here's the stats of the engines:

Horsepower: 446 @ 6200 rpm
Torque: 412 @5000 rpm
Compression Ratio: 10.9:1
Block: Cast Aluminum 6-Bolt
Crankshaft: Nodualr Iron
Heads, Chamber Size: Aluminum, Symetrical Port
Valves (I/E): 2.000"/1.550"
Camshaft, Lift (I/E): 0.500"/ 0.500" , Hydraulic roller
Camshaft Duration @ 0.050" I/E: 200/203 degrees
Intake Manifold: LS1 4-barrel
Part #17802134Price: $5,095.00

Based on the LS2 engine, the LS 364/440 ships with an aluminum LS block, which has a deep-skirt and six-bolt mains. Other features include light weight flat-top pistons with a 10.9:1 compression, powdered-metal rods, and a nodular iron crankshaft. The LS6-style cylinder heads are truly high performance pieces that deliver large amounts of air to the awaiting engine. The camshaft specs out with .500/.500-inch lift numbers, and has been specifically designed to work with the LS Family.

• 14-in automatic transmission flexplate included
• Requires aftermarket spark controller compatible with the 58X reluctor wheel and new cam sensing
• Intended for pre-1977 street vehicles and all off-road vehicles

or

GM Performance 19171224 - GM Performance Parts fuel injected 376CID/480HP LS3 Engine Details

Block (P/N 809-12584727): Cast Aluminum with 6-bolt, cross-bolted main caps
Bore x Stroke (in): 4.06 x 3.62 (103.25 x 92mm)
Camshaft duration (@.050 in): 219 degree intake / 228 degree exhaust
Camshaft type (P/N 809-88958733): Hydraulic roller
Compression ratio: 10.7:1
Connecting rods (P/N 809-12617570): Powdered metal
Crankshaft (P/N 809-12597569): Powdered metal
Cylinder heads (P/N 809-12598594): LS3 rectangle port; as cast with 68cc chambers
Displacement (cu in): 376 cu in (6.2L)
Engine type: LS Series Gen IV small-block V8
Maximum recommended RPM: 6600
Part number: 809-19171224
Pistons (P/N 809-19165089): Hypereutectic aluminum
Recommended fuel: 92 octane
Reluctor wheel: 58x
Rocker arm ratio: 1.7:1
Rocker arms (P/N 809-12569167 int): Investment cast, roller trunnion
Valve lift (in): .525" intake / .525" exhaust
Balanced: Internal
Valve size (in): 2.16 int / 1.59 exhaust

for $6895.99 w/o emc which is another $1000

[swb85]

For what you're wanting out of it, the LS2 would suit you just fine. Take some of the extra money you'd spend on the LS3 and install a better cam.

[Super73]

Agreed.. The $3k you saved going with an LS2, you could find a set of used ported LS1/6 heads and a medium cam and be putting down some decent power.

Any reason you would want to use the TH350 or 700 over a 4L80E? The 80E has many of benifits like being super strong, electronic control through the PCM for shift points, lock up TQ converter for even better mileage.

[GMC70c20]

i have a well built th-350 just sitting in my garage, I also figured for how much I'm going to drive it a little worse fuel economy wont hurt anything.

[olblue81]

I'm looking at the same swap as you c20. Just pricing the parts out to build a 408 with the block I already have and I'm way more money than the LS2. The way I see it, I would really have to want a 408 because the LS2 makes more financial sense. The LS3 and the 408 would be similarly priced, but the LS3 would make more power. I'm leaning more towards the LS2 and put a cam in it for sound effects.
What headers are you planning on using?

[GMC70c20]

L92's

[olblue81]

I'm wanting long tubes so I'd probably wait for Doug's. But this project is going to be a while so I have time.
Found this online http://paceperformance.com/index.asp...&ProdID=225248 and that looks real interesting to me.

[Super73]

You guys can probaably make a set of 98-02 F-bod Edelbrock Super Vic headers to work. They fit in my truck. I'm running the 1 3/4" stepped to 1 7/8 with high velocity merge collectors. the nice thing about them, since they are a slip fit collector, you can pull the collector off and put a piece of 1 3/4" pipe in the ends of the tube ans move them some if need be. Then slide the collector back on..