Is there 3.800" and 3.750" stroker?

Whitebowtie · May 28, 2004

Does anyone know if there is a 383 with 3.800" stroke and 4.000" bore, as well as a 383 with 3.750" stroke and 4.030" bore?

snoman · May 28, 2004

Got you thinking now huh. I really believe one of the strokes is bogus or not true. The real question is which one? As far as I know the 400 SM were 3.75 30 years ago but I myself have never seen a true 3.8 crank for a small block. I have seen 3.0, 3.25, 3.48, 3.75. 4.0 and 4.25 strokes for a small block and I "think" there was a 4.5 too (the 4.0 and above were aftermarket obviously).

Whitebowtie · May 29, 2004

How about this it list both a 3.800" and 3.750" cranks?

snoman · May 29, 2004

True but those are non GM crankshafts (aftermarket) and I am dealing with OEM parts and maintain that GM themselves never made a 3.8 stroker. (I am not tralk about a custom job only factory parts) I was reading a offroad magazine yesterday with a article about 4.125 stroker kit for a non standard deck height small block. It made 700plus HP and 700 plus ftlbs of torque with a mild blower on it!

sstruck383 · June 30, 2004

Yes, GM makes a 383 with a 3.800" stroke and 4.00" bore. GM sells the short block or just the crank. As far as more crank options, there are 3.875 as well. The 3.875 are used in a 396 or 427 small block.

jelisfc · July 21, 2004

GM sells crate motors like the one below and a HT383 version more for general use and towing in pickups.

NOW IN STOCK!!!! With GM’s legendary Fast Burn cylinder heads and 383 cubic inches, the ZZ383/425 delivers incredible torque with smooth, linear delivery. If you're looking for a small-block package that delivers big-block power, then you’ve found it. 425 horsepower at an incredibly low 5400 RPM, and 460 ft.lbs. of torque at 4500 RPM make this the ideal hot street engine.

The excellent air handling and combustion characteristics of the Fast Burn cylinder heads combined with the ZZ383/425’s 3.800" stroke, make this engine the benchmark against which all other 383 inch small-blocks should be measured. And it’s tough, too. The 4340 nitrided and induction hardened crank and unique forged PM rods see to that. The 9.7 to 1 compression ratio ensures that the ZZ383/425 is 92 octane pump gas friendly.

The ZZ383/425 gets a stout .509/.528 lift steel camshaft with 222/230 duration at .050 lift. Hydraulic roller lifters and GM’s time tested 1.5 to 1 roller rocker arms round out the valve train. And, of course, it has the Fast Burn head’s lightweight stainless steel valves and retainers for reliable performance at extended RPM.

GM’s testing was completed using a GM single plane intake, P/N 12496822 and a 750 CFM Demon carburetor with mechanical secondaries. Test header specs are: 1 3/4" primaries, 33 inches long with a 4-inch collectors. GM dual plane intake P/N 12366573 may be used for hood clearance on the ZZ383/425, but it results in a decrease in peak horsepower of approximately 15-20 horsepower.

PairOJugs · July 21, 2004

snoman, isn't this at least the second time you've tried to disprove what you've already seen in type? GM doesn't build new engines with a .030" overbore, and it costs no more to build their own new crank and pistons in 3.8" as well as 3.75", so that's what they did. these were not made on vintage 1970 tooling, so it's not like they went out of their way to make the stroke they wanted.