I've got an '88 E350 4x4 van with the EFI 460 in it. I'd like to rebuild it with 10:1 compression, better exhaust flow (ported heads and new exhaust), but little else. I'm leaning towards swapping the speed-density EFI for carb.
Questions:
1.) Will a 429 (any year) swap with this 460? (C6 tranny)
2.) I've heard the '71 429/460 heads had a "squish zone" to reduce pre-detonation and allow for higher compression. Is this available on newer aftermarket heads?
3.) Port the current heads, or buy new ones? If new, which ones?
4.) Headers vs. manifolds?

The van has 3.54 gearing with 33's on it and weighs almost 8000 lbs. empty. At 70, it's spinning around 2700 rpm. I don't tow, but do drive the mountains in Oregon frequently. Like to hit around 400 hp for minimal mileage decrease. Currently getting 10 mpg.

Thanks,
Fish

 

You cant throw a older carb style engine under that injection. The heads are different on the intake and exaust ports for starts. That injection is speed density and you will run into big drivability problems when you step up to a big cam and alot of compresion and the computer wont understand whats going on. I would just rebuild your engine with all the good stuff, forged pistons, good rod bolts and have some very miner port work done. Have a complete exaust system done too. Go Thorley's (I think it Dougs Header know) and go with a single 3 1/2 inch system with a high flow cat and a Flow Master. Then later on throw a Vortec or Paxton supers charger on it. I think you would be happy with that setup. Good luck.
Chris