I used to have a 67 BB Stang too. (with both a 390 and later a 454 side oiler/ low riser stroker)The stock cam specs for the GT390 aren't all that different than the F4TE roller. I ran a Holman/Moody solid in my 427, this was their "Bonneville" cam. The advertisd duration was 310/310. The gross valve lift was .515. Sounded wicked as hell, but compared to many others today, it's specs are pretty tame. The specs on the F4TE are 256/266 (advertised duration) lift with 1.7 rockers is .445/.473 with a 116.5 LSA (this is where the compression/detonation comes in, it generates more dynamic compression with it's zero overlap) The HO 5.0 cam specs are 266/266 with 1.7's the lift is .473/.473.(not much of an upgrade when you look at the specs, I only recommend it when someone already has the cam in hand) Your GT390's cam stock cam specs were 270/290 (advertised duration) .481/.490 lift. The regular 390's cam was almost the same in specs as the F4TE cam in both duration and lift. I know it's hard to compare advertised durations between cams, but the roller will have faster ramps than those old flat tappet grinds. You're sitting there telling me that I need a bigger cam, without knowing what the specs are to start with. I'm not trying to put you down, but I'm speaking from 35 years of experience in both FE's and small blocks. I've built my own engines as well, nobody did it but myself and a friend or two. I've run the cams I'm talking about. Granted the 390 had better heads, but the cam specs aren't all that different between them. Once again, I'm not building a hot rod engine here, only a low rpm, higher torque engine for use in a full size van. The F4TE will do fine, provided the static comp ratio isn't too high to start with.

 

I never said "bigger", I said BETTER. Very different between the two.
You sound like you've done some cam research. But you still are compromising compression ratio to keep the f4 cam happy in my opinion.
If there were a cam that you could run the higher compression ratio, would you?

 

There's a tradeoff between the two. A cam that bleeds off cylinder pressure generally also bleeds off fuel economy via a narrower LSA. Ford has done their homework on their roller cams. I've read the book. They've got more research time under their belts than any of the major cam companies. The higher ratio nets you nothing if it the cam bleeds off cylinder pressure. The trend now is to variable cam timing. That does wonders that cannot be done without it.

 

Well we picked up the 96 van this weekend. It's got an exhaust leak at the manifold/head junction on # 2 & 4 ports, otherwise runs fantastic considering I have no idea when it was last tuned up (if ever at 97K miles) Has the original plug wires. No smog pump, never had it. The cats have been removed (I guess that's why the dealer focused on selling it out of Texas) Has a 3.55 rear. The stock width wheels don't fill the rear fender flares, so I'm going to do what I did with my old 95 van, and swap wheels and put 15/10's in the rear with 275/60/15's and improve the gear ratio at the ground to 3.67's. Thinking now on just doing a head swap to GT40's and shorty's, topped with Cobra rockers instead of the full on stroker. (might still do that later on if I want) The gas mileage was great, considering the dealer filled it with the cheapest gas he could find, first fillup netted 14.25 mpg, mostly highway driving at 65-70 mph.

 

Couldn't you use the 19 lb. injectors in the stroker motor that you put in the van, and see if you get trouble codes indicating a lean condition?

If there is no such problem diagnosed by the computer, then maybe you could just leave in the 19 lb. injectors.

 

I'll have to put a code reader on it afterwards to see what's going on, the CEL is lit now, but I suspect it's from the missing cats. First off gotta get the heads reworked.