Zz 383

[ryan_prettyman]

I have a 97 silverado regular cab 2wd with vortec 5.7 I was wondering if anybody has installed the ZZ383 under the stock injection and if the cam is to big or not computer friendly I will deal with the injection later just need new engine I was thinking of using the MP 122H later to solve the fuel problem, and who is the best to do the tuning?

[YenkoST]

The stock fuel injection is not enough to feed that hungry sucker. You will need a Marine intake conversion or some type of MPFI. The 122H would be a great kit but you'll have to custom fit it to work. Where are you located in GA. If you in the SE, I can hook you up with a local tuner around here otherwise Nelson or Wester's would be your best bet.

[Pauly]

I have seen the ZZ383 installed in a Vortec 350 van, it ran lean at higher rpm's. The install was done at a GM dealership.

Westers did the tune. The HT 383 was on national backorder so the ZZ383 went in. 425 hp and 460 lb/ft of torque.

You could try drilling out teh stock fuel pressure regulator (stock is 4 BAR or 58 psi) and run the fuel pressure up to 80-85 psi. If you installed teh GM upgraded MPFI spider, you can run a continuous 100 psi with the injectors locking up.
post #9 of this thread shows pics of teh stock CSFI spider, the newerMPFI spider, and teh stock truck and MArine intake manifolds.

here is some info on teh newer GM MPFI upgrade
http://www.pacific-audio.com/performance/messages/231640.html
and here
http://www.pacificp.com/forum/viewtopic.php?t=981




A Ramjet or marine intake or carb intake converted for fuel injection would be best.

the ZZ383 has D port exhaust ports which require some work on teh exhaust manifolds or large tube 1 3/4" or larger primary headers will cover the D ports. These D ports are teh same as used on teh LT1/LT4 Vetes, Camaros and Firebirds, hint hint.

The Fastburns aluminum heads which are atop the ZZ383 have large 210cc intake ports which dont help with off idle torque.

In the van install, the stock manifolds and tiny and crimped down dual 1-7/8" pipes and teh restrictive L31 Vortec intake manifold certainly would take away from the ZZ383's power, which was rated with a 750 cft double pumper and LT headers with 1-3/4" primaries that are 33" long with huge 4" collectors. These restrictions no doubt helped keep teh engines power down and therefore its fuel needs down as well.

You can make that zz383 work, it just requires some ENGINuity.

Dont worry about that 222°/230° cam, thats not so big on a 383. It will sound nice though.

If the MP112H is the Maggie blower I think you are talking about, that certainly wont make your fuel problems any better, unless it is this Maggie that IS destined for Vortec heads, notice the ALL IMPORTANT conventional replaceable fuel injectors, now drop that on a ZZ383, that would be astounding.
http://www.magnacharger.com/images/highres/Gen1E%20Small%20Block%20Chevy/Gen1E%20Photo%201.jpg

You will need to install the front timing cover from the L31 as well as the reluctor wheel and Crank position sensor (CKP) sensor from teh L31, as well as the balancer form the L31 as the L31 balancer is machined thinner to allow clearance for the thickness of the reluctor wheel. Dont worry the HT and ZZ 383 engines use a 3.80" stroke crank which is internally balanced unlike the externally balanced 400 SBC that's crank is NORMALLY used for regular 383 engines. GM uses a 4340 forged steel cranke, hi po PM rods tested at 550 hp at 6000 rpm for 45 hours at WOT, tehse rods are stronger than the older hi-po "pink rods" of lore.

I wish I knew where that van with the ZZ383 went, I could "borrow" the PCM tune for you.

post back with any questions, I love bench racing about Vortec L31 350 and 305 L30 stuff, I am jealous, I would LOVE a ZZ383 in my truck, I could actually use the 28 pph injctors that are in there.

peace
PAuly