00fxd

Hi all. I am in need of some advise. I am about to embark on swapping out my TBI sb400 for an Lsx. I have access to a real good LQ9 but I would like to hold out for an all aluminum L76. I am going to stick with my Muncie 4spd. I don't plan to swap cams or anything, pretty well run it as is. If I go with the L76, what issues might I run into with the variable valve timing etc or DOD? Should I retain that feature or can it/should it be programed out when I have tha VATS disabled? Do I have to replace lifters or anything if the DOD goes? Is there any reasonable solution for the VSS? And finally, I understand that the Muncie falls short in the input shat length department by about 5/8". Is there an adapting bushing or anything out there? Thanks Frank.

ChucksZ06

iTrader: (9)

Frank,
Just get a bearing that fits in the large outer hole of the ls crank. Kiesler also makes a nice bellhousing for muncie application if you do not have one.

chuck

00fxd

Thanks Chuck. Have you tried this? I got the impression in the past that the input shaft is too short but there was a solution.
Is this the right place to be asking these DOD related questions?
Frank.

00fxd

to some one who can answer my questions? Is this the wrong forum? I would really like to know it would take to make an L76 work in my old Corvette.
Thanks, Frank.

68 RS Convertible

iTrader: (1)

As far as running the Muncie goes you can also go to Pace Performance GMPP (Jim Pace Pontiac). They have a bellhousing that is designed shallower for lack of a better term to bring the trany up (closer to the motor) that little bit. I actually bought one, three hundred some odd bucks later and measured the depth vs my stock bell housing. There was like 3/16 difference, if I remember correctly. I mocked up my motor, bellhousing, trany (when I finally got my block back from the machine shop) and found that the input shaft set in plenty with my stock bell housing. Needless to say I returned the bellhousing to Pace. I think you will find that if mock your Muncie up the input shaft will set in the pilot shaft bushing/bearing enough to get the job done. I also let the me pilot shaft bushing set out of the end of crank by a hair. I mocked up with both a Muncie and the Tremec TKO that is in there now, they are supposed to be dimensionally the same. As far as I know, someone correct me if I'm wrong, you only need the input shaft to set in enough to keep the input shaft from walking around when your clutch is engaged. Can't help with the DOD stuff, you may want to try the Gen IV Internals forum for that stuff.

00fxd

Thanks a lot 68, great to hear from someone who has been there done that - now if Hooker would come out with LSx side pipe headers for the Corvette in time for me in the swap section of the catalogue that would aleveate another small headache.

luckyhenriksen

iTrader: (1)

Couldn't you get LS headers and modify them to fit your existing side pipes? Just a thought, I know nothing about early corvettes.

00fxd

Yep, that's the plan, but Hooker has traditionally an "engine swap" section in their catalogue. They are offering headers for first gen Camaros/LSx swap now so I hope headers for their popular Corvette sidepipes are coming soon.

garys 68

iTrader: (1)

Your small block bell housing wont work. Get a big block "621" bell housing with corvette throwout fork from Keisler. The bell housing is drilled for the extra LS bolt.
You'll need an LS7 pilot bearing. I got mine from SDparts, it fits in the larger outside crank hole.
Get a longer Timkin 1377C throwout bearing, you'll have better geometry with the LS clutch.
You wont need VSS for anything other than VVT or DOD, so I would go for the LQ9 block or get rid of the VVT.

Hotrod406

iTrader: (6)

My small block bellhousing would have worked fine but I got an SFI swap unit for safety. The only difference was the extra bolt hole at the top for the LS bellhousing pattern. I had to trim it on both sides so my headers would fit too.

I agree on that extended throw out bearing. I'm using the stock one with an adjustable pivot ball and it is maxed out. I don't dare to extend the ball any more than it is. It works fine, but that other TO bearing will probably work better.

The pilot bearing I got goes in the large diameter at the back of the crank and works great. I don't have the part number anymore. It might be 12557583

garys 68

iTrader: (1)

The larger LS clutch would not clear the 153 tooth bell housing on my application.

Hotrod406

iTrader: (6)

Mine had the 168 tooth for some reason. It's a base motor 71. I didn't know they had different bellhousings.

garys 68

iTrader: (1)

Pre 69 SBC were all 153 tooth.
BTW, I'm guessing on that throwout bearing. I mocked up the Richmond 6 speed yesterday and found the same thing you pointed out. The effort to engage the clutch was also kind of high, probably because of the geometry.
I got the specs on about a half dozen throwout bearings and the 1377 looked best. Now I just gotta find one, no one has them in stock around here.

jfg455

iTrader: (5)

The VVT you can keep and run with the stock PCM if you want to. Or you can change the front cover, cam, sproket and not use it. Same with the DOD, just change the top engine cover and lifters, program it out and viola!. I would like to see more poeple keep it and use it for the power potential and MPG personally.

00fxd

Thanks jfg455 and everyone. Thats the way I'll go then. Can you recomend a programer that I can send my PCM to? I'm gonna needs some ideas for a Vehicle Speed Sensor as well..
I allready have an 11" clutch/168tooth Bell Housing so I should be ok bellhousing wise then. It's an old cast iron thing from an early 60's truck 'cause I'm a dinosaur. I had to trim the back ear mounts off it so I can trim some more if I have to.
I'm selling off my sb400/TBI/Holley Thottle body so the projects a go.
gary's68 why wouldn't the LQ9 use a VSS?
Great info everyone, thanks.
Best regards, Frank

garys 68

iTrader: (1)

My LQ9 doesn't have VVT or DOD so it doesnt need VSS, especially with a manual trans. You dont need VSS. Your Muncie wont have a VSS output. There are adapters to get a GM recognizable VSS output, so you'll need to add that to get those parts to work.

00fxd

Gary, my obd1 throttle body injection [1980 truck] requires a VSS to work correctly. With out one the thing will stall coming to a stop etc. I have an aftermarket speedo cable driven VSS that sends the required 2 wave signal to my ecm. 2000 pulses per mile. I understand the obd2 [LS engines]requires a 4 wave to opertate correctly. Gawd knows what the later stuff requires.

garys 68

iTrader: (1)

My understanding is that the stalling issue without VSS is only with automatic transmissions. Your thoughts?

LS1MCSS

iTrader: (18)

If you do decide to run a VSS, http://www.jagsthatrun.com/ has a 4 pulse(two wire) vss that will mount onto your speedo output on the tranny. The speedometer cable will mount onto the vss so you can run the original speedometer.

00fxd

LS1MCCSS, Thanks for the reminder, I havn't looked at JTR's site for a while.
Gary, here's a good write up on VSS. http://www.jagsthatrun.com/V8-chapte...ed-Sensors.pdf