Vortec 350 & 3 on the Tree fitment

[curvedglass]

Hi Gang,

Looking at GM Performance web site it looks like the Mexican 350's are no longer produced. I see the oldest fitment is an 87-96 vortec 350 with the bolt thru valve covers. Brand new. Same 210 HP etc 3 yr warranty. I plan on keeping my 3 speed on the column. I also have plans to install one with an overdrive unit. Can I bolt the trans behind one of these with a one piece rear main seal? Is there a spot for the clutch pivot? If neither, how to make it work? I have seen pics on this site vortecs but no specific transmissions.

Thanks in advance.

[RustyPile]

The one-piece seal engine requires its own flywheel. All that is needed here is the pilot bearing.. IIRC, the 87 - 96 block should have the hole for the "Z bar" pivot ball. Your TOTT bell housing, clutch, T/O bearing along with the T/O fork will all fit.. It's literally a "bolt up and play" installation..

[bhap]

I thought they were producing the L31's again (just more $$)? I have an L31 with a Saginaw OD (from a car), three on the tree in my 62. I kept the hydraulic clutch setup and the 60-62 bellhousing, but the hole is there on my block for the clutch pivot. I used the original bellhousing and crossmember to locate the engine and shimmed a set of 67-72 engine mounts for the front mounts. So I ended up with a 4 point engine mounting which so far has not seemed too "harsh". The Saginaw OD went in fairly easily - my driveshaft was the right length but I needed a new front coupler because of the difference in splines. For shift rods, one worked "as-is" and the other needed to be lengthened about 2-3". There is a write-up on the forum somewhere with the dimensions for making the shift rod longer. I have 3.38 gears, so when I engage overdrive rpms are in the 1,700-1,800 range at 65-70 mph. I'm thinking 3.73's would probably be about right. One thing I wouldn't bother with next time is the kickdown switch connected to the throttle. It requires flooring the accelerator to effect the downshift out of overdrive for passing or acceleration. This seems a bit "violent" to me. What I did was install a simple toggle switch that I can turn off when I want to downshift. I lift my foot from the pedal, turn the switch off and the trans goes out of OD and I'm back on the gas. I have the kickdown switch setup and adjusted, but just don't like it. I also like to turn off the toggle switch when not using overdrive because I don't think the solenoid needs to keep trying to engage when you hit 45 mph. Let me know if you have questions, I'm glad to try and help.

It looks like the L31 is available: https://sdparts.com/i-24502361-gm-en...8uqgrSuuZArf9l