hey have a firewall question

[philadelphia]

Hey everybody. I just found this site and like the vibe.I am currently working on a 88 cab and chassis truck. Its a 454/th400/205 truck, dually with a front 60 and 14bolt. Im swapping out the cab to a crew cab but its pretty rusty at the rockers..I got two suburban rokers and started installing those. I have to  still do the cab corners and  prep for paint.

So far ive sandblasted and painted the firewall but my two door has AC and i want to keep that.The crew is a heat only cab..Im wondering are the firewalls different.I want to run the entire ac setup.I have already painted the firewall with black wrinkle paint so im hopeing that i dont have to cut a section out..From peeping at the firewalls in the yard it seems that they are different.

Id really like to keep the ac but if the firewalls are way different then i guess i can run the heat only and use the compressor ffor on board air.

Truck is gonna be a daily driver/tow pig to pull my trail truck.

[HAULIN IT]

The firewall is the same, the holes for mounting the evap box & it's parts, ect. are what is different. You can cut/drill in a few places & swap the a/c over to the other cab. If you do a search on here you will find the details. Basically, You cut an approximate hole 6"x8" for the evaporator core, drill several holes for the hoses, wiring & box mounting, then bolt everything in. I used the A/C firewall & made a template from poster board & transfered all of the holes. Have Fun, Lorne

[philadelphia]

Thanks.. Good to know..Im hopeing to get this truck running by march.I just moved back to new york so im getting used to seeing rust..This truck needs new rockers and a floor on the drivers side as well as cab corners.It would have been better to get a crew cab truck but i dont have cash to spend in lump sums.

Im replacing the rockers with used ones i cut from a suburban and im gonna try to ush the cab corners and half of the rockers from the 2 dr onto the 4 door..I have just ordered new cab corners just in case.Once i get this done i want to get the 2 dr cab off and set the 4 dr cab on the frame and start swapping electronics etc.