The stock Powdered Metal forged stock rods are excellent pieces and are stronger thyan the older "pink" bowtie rods. The design is tested to 500hp, you will run out of fuel before you come near the limits of the stock rods. You also have to remember than with the stock Blackbox PCM in these 1996-1999 GMT400 Chev and GMC trucks, you wont be able to rev over 6000rpm anyways. The stock fuel shutoff is set at 5600rpm and even if this is reset via PCM tuning to 7500rpm, the PCM's hard rev limit is 6000rpm. You can do a 0411 PCM swap and then have the ability to rev 8500rpm if you wish. The 2001-2002 Express vans used the newer 512 kb 0411 PCM with the dual 80-pin connectors and used it to control the same Vortec 305/350 engines that our trucks used. The 0411 PCM opens up tuning support for the 1996-97 trucks(as only Tunercats OBD2 and JET DST and Westers GMT support the 96 and 97 blackbox Vortec PCM's) EFILive and HPTuners support the 1998-2000 blackbox PCM's although the support is limited. Basically upgrading to the 411 PCM opens the Vortec 350 tuning right up. A guy named Lextech has taken the van and the truck pinouts and compiled a swap sheet to retrofit the 411 PCM from the blackbox PCM. Different sheets for the 96 and 97 and the 98-00 GMT 400 trucks as there are differences between these 3 model years of trucks.
The stock -13cc dish pistons stock are hypereutectic(high silicon) pistons in between forged and cast aluminum pistons.
The stock crank is an excellent nodular iron piece.
Stock cam specs are 191º/196º at 0.050" lift of 0.412"/0.428" on a 111ºLSA this cam is ised in the 1996-2003 Vortec 350 and 305, and also the 1994-96 iron headed LT1 in the 94-96 Caprice-Wagon/Impala SS, Buick Roadmaster/Wagon and Cadillac 5.7 liter engines and also used in the 94-96 200hp GEN 2 4.3l V8 L99 engine.
The RAmjet 350/HT383/MArine 350-383 roller cam you got specs at 196º/206º duration at 0.050" and 0.431"/0.451" on a 109ºLSA. On the Ramjet 350 crate engine, this same cam is ued with the 1.6:1 roller rockers which brings valve lift up to 0.461"/0.481".
If you run any of the Beehive springs such as 26915 or 26918 Comp Cams, or PAC 1218 or 2002-2004 LS6 Beehives along with the special Comp Cams 787-16 retainers that work with the Beehive springs AND the GEN 1 SBC valve diameters which is different than the 774-14 which is the beehive retainer you'd use wit the GEN 3/4 engines, you will have 0.550" clearance on stock unmodified Vortec heads.
This thread has all the parts/specs and pictures with Verniers showing the actual clearance on stock Vortec heads
GM Performance :: View topic - LT4 Hotcam in L31
I'd be a tad nervous of running a 64cc chamber with a flat top piston
With flat tops, I get 10.90:1
With the 193's and their -12cc dish I get 9.55:1. With the numbers supplied in post#1.
We have to remember that the GEN 2 LT1's are both reverse cooled, and the performance LT1's have aluminum heads.
The stock Vortec 350 is rated at 255 sae net hp@4600rpm/330 lb/ft torque@2800rpm. If you take that same engine and measure it on an engine dyno, it will dyno at 310-320 gross.
The stock CSFI or GM upgraded MPFI spiders will limit naturally aspirated power to around 390-400 crank hp.
Stock Central Sequential Fuel Injection above the GM replacement Multi Port Fuel Injection spider. For MY 2004 the vortec V6 used these upgraded spider injectors(both of these units flow exactly the same, which is 24.3 lb/hr at 63 psi fuel pressure.
I use the marine intake, pictured left stock intake right, and use 29 lb/hr injectors(at 58 psi fuel pressure)
The RAmjet intake will also work, with a bit more work than the marine intake
Ramjet intake on Vortec 350 using a CNP ignition kit.
Any intake will work, so long as you can plumb fuel injectors that can be sized to you power/fuel needs.
peace
Hog