'86 VSS Signal?

[y5e06]

When seaching I came across this thread
http://67-72chevytrucks.com/vboard/s....php?p=3505118

I'm researching swapping a 2002+ 5.3L into my '86 2500 Suburban in place of the carb'ed 454. I'll be keeping the TH400 and just use an adapter plate.
When looking at my carb I just looks like a regular ol' quadrajet, it doesn't have TPS like my stock '87 Monte QJet does. I'm fairly sure it is the original. Anyway, the above thread indicates feedback carbs may have an integral VSS for the instrument cluster & cruise. My TH400 uses the old fashioned cable drive. how do I know if it is a feedback carb? What signal does the '86 cruise control use maintain speed?
so, how can I be sure my truck has a VSS signal? and if it does, what is the signal output from either the VSS or VSS buffer? is it a square wave after the buffer or AC sine wave? The late model 5.3L engines use VSS which looks for 40 pulse per driveshaft rotation sine wave. I'm trying to figure out if I can some how use this signal for the 5.3L PCM, with program adjustment of course.

If sine wave I can adjust with the program. If square wave I think I might be able to source a box for a 90's S10 (DRAC? I think thats what it is called) to convert to sine wave. Any ideas? This is a budget build so I don't want to go out spending tons of money on items I might be able to piece together cheaply.

If no VSS at all, I'll have to figure out some thing else.

oh yeah, this is my 1st post...

thanks,
Morgan
'86 'Burb 454 TH400 14Bolt FF

[b454rat]

There should be a VSS signal on the back of the speedo, used for cruise I believe. If not, I know 87 will have one. I'm not sure, but don't think that VSS is enough to run the newer stuff.

[clinebarger]

The photo-optical speed sensor in the cluster even with the help of a buffer will not marry to a late computer. the 5.3 computer has a built in buffer (analog signal in, digital signal out to the TAC/cruise module,antilock,body control modle, insterment cluster)

Your only choice is to have a analog(hall effect) VSS. Street & Performance has a conversion tail-housing with mechanical drive and a VSS for a 4L80E maybe it whould fit a TH400. the phone #479 394 5711 / www.hotrodlane.cc

I had to buy a tail-housing from them to run both on my 3/4 suburban but it was for a 4L60E

[y5e06]

Well, thats no good. oh well.
my current plan is to use a pass-through add on VSS sender. see item #3 here
http://www.jagsthatrun.com/Pages/Spe...eedometer.html

puts out a sine pulse that looks like might be compatible w/ the 5.3L pcm, it will just need programming adjustment for counts.

Thanks for the responses. I was hoping to get around an additional add-on and spending more for the project.

[clinebarger]

Great find.