With all the up & down temperature swings have been working every minute outside when it's near 50 degrees & warmer. 62 today
. Will clear out more PM room tonight.
On the one piece trunk pans, the following is what I was told again late this Fall, in regards to one piece trunk pans. This was from long time bodyman who has a TON of hands on high quality experience replacing rear sheetmetal under '68-72 GM A-body's. "As far as reproduction one piece trunk pans go, there is a '68-69 LeMans/GTO one piece trunk pan and there is is a '70 Chevelle one piece trunk pan". Several of us have the confirmed viw after a lot of examination that neither one piece trunk pan is a 100% install into a '70 LeMans/GTO or a '71-72 LeMans/GTO (or a 442, for that matter). The differences are in regard to the furthest rear stamping, ESP the stamping as to how it is shaped on each side where the back of the rear 1/4 ties in.
Another very experienced body man that am working with, showed me a one piece '70 Chevelle trunk pan he had recently installed in a '71 W30 442 (he has also started metal work on my long time customer's '70 GTO). On the '71 442, he was reusing the furthest rear trunk structure out of the 442.He was also reusing the 71 trunk floors front shelf area as the '71-72 front "shelf area" is different than the '70 front pan/shelf area.
Am fortunate, my '71 & 72 Pontiac A-bodys have fairly nice bodys with rock solid original pans. Even my previous '71 Judge project which needed 1/4 panels & outer wheel houses had very solid floors & trunk & retains them today. Have broken down partscars before for these complete original panels & have several parts cars with perfect trunk floors & rear structure in them, so know a little about them, with one '72 partscar being disected very soon. It's just time consuming to drill all the spotwelds out & remove both quarter panels to get the back halve of a solid A-body down a clean rear structure/ full trunk pan with complete wheelhouses. Due to time concerns, what we ended up going with for the '70 GTO was a 3 piece trunk pan, as the GTO's inner wheel houses & the rear trunk floor (where it kicks up) as well as the reinforced structure behind it were not rusty at all. My suggestion was that we pick up a 3 piece trunk floor, as not only is the 3 piece much less costly, but much easier to install. Our longtime A-body bodyman concurred.. The weld lines will be over the trunk braces & carefully buttwelded, ground down, with very minimal filler, and will not be seen. Deciding to go that way, our next huge concern with the 3 piece was there enough kickup to the rear of the pan to splice it into the existing structure? The 3 piece kicks up about 5 inches so it no problem. This partiicular customer's '70 also neededa pair of full 1/4 panel's, outer wheelhouses, trunk drops, & floor pans halves. Front floor pans were a little soft, mid & reese floor pans were solid.. Ended up making a drive, saved close to $800 over rhe most reasonable catalogue vendors. Picked up all reproduction sheetmetal but the trunk drops, which had to be drop shipped from the Mfg & were here in a week. Though the trunk drops are made in the USA, they will need a little tweaking to fit, there is so much going on back there, that this did not surprise us. Hope this helps, without knowing how extensive the rust is in your trunk area, I can only relate our recent decision.
*Note: the front trunk shelf area, for a long time,has been a good place to examine and spot when non ethical "restorers" have used '71 & 72 "bodyshells" to "restore" '70 model A-body's (or vice versa) Unfortunately, have ran across such body swaps several times. Typically, not a happy ending, ESP when the car has been represented as something that it isn't.