P12 vs P30 chassis

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Jun 10, 2019
OK, I'm thoroughly confused. I just bought a 1999 Winnebago Vectra GT and was looking up parts (alternator, starter, belts, etc.) and noticed that the only sub listing I could find the parts under was a Chevy P30 chassis. The advertisement from Winnebago states it's on a P-12 chassis. Then I noticed that other forums state that this rig could possibly be sitting on a Workhorse "P" chassis. Again, looking at autozone.com (or even rockauto.com), Workhorse shows up with a P32 and a P42 chassis. My VIN indicates a 1 ton chassis (6th digit is a "3"). Any ideas on what I'm riding on? Is there major differences in parts between the two chassis (Chevy v. Workhorse)? From what I can tell, the major difference between the two is the front end width and suspension choices. Is that where it ends or is the more differences? Thanks for any help!

UPDATE: I spoke with Winnebago, and after a little back and forth between them and Workhorse, turns out its on a Chevy series CP32012. I will use that to get part numbers for the engine when needed. Hope this info helps out anyone else in the same predicament!
Workhorse was just beginning to take over the Chevy chassis business in 1999. Workhorse itself never built a P12 - their VINs only reflect P32 or P42 for the P-series chassis. If you have a P12 of 1999 vintage, it should be pure Chevy. The first 3 characters of the VIN will identify the manufacturer as either Chevrolet (1GB) or Workhorse (5B4).

A 1999 motorhome often has a 1998 chassis, which is probably what your chassis VIN will show.

Please post the VIN and we can help you decode it to identify thigs more specifically.
This previous topic may help shed some light on the very confusing P-series chassis designations.
Just to clarify here, Workhorse bought out Chevrolet's P series product line on January, 1999 here is an article that talks about it a bit, note I have often seen June / July, 2001 listed as actual production introduction of the Wide Track Front end P32, so I am not sure about this discrepancy

Workhorse took over production on 1/1/1999 but did not do any P-series design improvements right away.  It wasn't until 2000 that any changes appeared and there were a steady stream of improvements in subsequent years.  The wider track front suspension came in 2000, the larger GVWR suspensions appeared in 2001 & 2002, the 8.1L engine in 2002, the 4L85E transmission in 2003, etc. All these and more are described in the Workhorse Chassis Guide but none are germane to a P12 (cause Workhorse never built that chassis).
You can get a P12 chassis service manual on Amazon for around $15. Recommended for P12 owners.

It's my understanding the P12 was produced for only a year or so, around 1998.  It was intended to provide a larger, more capable chassis for the larger gas motorhomes the market was demanding.  Chevy stopped work in it when they sold their chassis business to Workhorse and Workhorse had their own plans for the W20/W22 series chassis.
They are also very rare, only a few were ever built, and some of the front suspension parts are unobtainable

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