Sorry this is a little off the forum, but ZZ3's could be used in a smaller boat. A lot of you folks on the board have hot rods, is anyone running an over - the - counter Chevy ZZ3 smallblock? This is the forged steel connecting rod version of the ZZ4.

The question is, what spark plugs are you running?

MY partner ran a pair of ZZ3 's in 27 Hallet ran great for approx 350 hrs until replaced with 383's...never a minutes trouble with the crate motors

KL

I try to run NGKs in everything.

Hi Ed - I agree on the NGK's but what I'm looking for here is a plug #.

Aha! Okay, but I need more info.
Tell me what plugs are in there now, or do the heads need 3/8" or 3/4" reach threads.
You can get extended electrodes or not depending on application and usage.
The more info you have, the better I can get you in the right ballpark with the plug that will give you the best service in real-life conditions.

Thanks Ed. Thats part of the problem, the engine was a takeout from another Vette that I bought and I don't trust the guys that put that car together. The engine had NGK TR5 V - Power plugs, BUT are they correct?. The heads are the late model aluminum angle plug Chevy heads that come on the over the counter engines.

Here's the spec section for ZZ-4, including plugs. I don't have a ZZ-3 in my catalog.

-Greg
HO 350 SPECIFICATIONS
Part Number: 24502609 (ZZ4)
Displacement: 350 cu. inches (5.7-liter)
Horsepower: 355 at 5250
Torque: 405 lb-ft at 3500
Bore & Stroke: 4.00" x 3.48"
Compression Ratio: 10:1
Engine Block: Cast iron with 4-bolt intermediate main bearing caps
(P/N10105123)
Crankshaft: Undercut and rolled fillet LT4 nodular iron crankshaft.
Connecting Rods: Steel P/N 10108688
Pistons: High silicon aluminum piston with offset pins (P/N 10159436)
Piston Ring: 14089025
Camshaft: Hydraulic roller tappet (P/N 10185071)
Valve Lift (Intake/Exhaust): .474"/.510"
Duration (Intake/Exhaust): .208/.221 degrees at .050" tappet lift
Valve Lash (Intake/Exhaust): Zero/Zero
Cylinder Heads: Cast aluminum, 58cc chambers, angled spark plugs, screw-in
rocker studs (P/N 12556463)
Intake Valve: (1.94") P/N 10168465 Exhaust Valve: (1.50") P/N 10168514
Valve Springs: LT4 chrome silicon 1.340" diameter (P/N 12551483)
Rocker Arm Ratio: 1.5:1
Distributor: High Energy Ignition with centrifugal and vacuum advance (P/N
1103436)
Initial Spark Setting: 10° BTC @ 800 rpm with a maximum of 32° at 4000
rpm with vacuum advance disconnected.
Spark Plugs: AC FR5LS, 904, or MR43LTS
Maximum Recommended Engine Speed: 5800 rpm
Fuel Requirement: Premium unleaded (92 octane)