I would like to know if there is a website that can recommend the correct stall speed. Or maybe I could get some ideas from all of you. I am ordering Monday from atechmotorsports. Thanks in advance!


Car specs: 89 iroc, 700r4, 2001 10 bolt w/3:23, stock rims and tires

Engine Specifications and Features:

• Horsepower: 425 @ 5400 & Torque: 460 @ 4500
• Max. Recommended RPM: 6000
• 9.6:1 Compression Ratio
• 4340 Crankshaft: Forged Steel
• HD PM Connecting Rods GM#10108688
• Camshaft 12370846 (hydraulic roller): -Gross Lift (.509 I / .528 E.) -Duration @ .050 (222 I / 230 E).
• GM Fast Burn 12464298 aluminum heads w/62cc. combustion chambers.
• Rockers: 1.5:1 Roller Rocker
• Cast iron 4 bolt main block
• 8” GM Performance Balancer
• GM aluminum single-plane intake manifold.
• GMPP/Holley 750CFM Carb w/vac secondaries
• GM Performance curve HEI distributor.
• GM Performance Plug wires
• GM Performance fuel pump (plumbed pump to carb)
• GM Performance High Torque Starter
• 12.75” A/T Flywheel
• Chevy Fabricated Aluminum Valve Covers & Air Cleaner

I think I am looking at either a 2500 or a 3000 stall. My future upgrades are going to be 3:42's or 3:73's, and a t56.

The only consideration for stall speed is the camshaft's advertised duration.

Doing a search, 12370846 is a GM camshaft found in the ZZ383 engine. It's considered an off road camshaft and I can't find advertised duration for it. Nobody seems to list the advertised duration for this cam.

I'm going to take a guess based on any Comp Cam with similar specs and recommend a stall speed of 2200 and 2500 would be pushing it. It doesn't have enough duration for more stall speed.

I answered this over in the engines forum where you first posted it, please go look.

Actually I did catch your post thanks (Atilla), and thanks to Stephen also, both of which helped with the quick replies. I ordered A 2500 stall today (non-lockup). A hughes performance premium race rebuild kit with kolene steels, the transgo 700-2-3 shift kit, servo's, and all the other goodies I need. Thanks again!

if you order a non-lockup converter for a 700R-4, there may be something else you have to do. I'm not sure, as I love the lockup, and I hated my B&M TorkMaster2400 when it wasn't locked and I wasn't in first gear.

really? D*** I did a search and found nothing. But thanks for the heads up, I will keep searching. The tranny shop said with that motor the best thing would be no lockup.

That thing should easily manage a lockup, with no lugging and none of that so-called trailer-hitching feel, if you get rhe carb and spark dialed in well. A good 2500 stall converter will slip about 200 rpm at cruise, and about 400 rpm at WOT. A crappy 2400 stall will slip as much as 1200 rpm at WOT.
Likewise, a crappy 240o stall will run 2400 rpm down the interstate even when the gearing calls for 1800, so it generates alot of heat in the ATF and wastes alot of gas.
Only old-school mechanics distrust the lockup. But since you ordered that, I'd suggest 2 things. One, call B&M's tech line and ask if you hafta do anything to the trans to use a non-lock converter, and 2, get a B&M auxillary fluid cooler, install it so the fluid goes through the radiator first, then the cooler, then back to the trans.