keep in mind alot of the power difference in the H.O. vs std 302 was in the injection and fuel mapping. the H.O. engine was also "SEFI" trucks untill 96 maybe 95 were "bank" fired. meaning the trucks would fire all 4 injectors at once 1 bank at time and SEFI fired the appropriate injector and the right time. the trucks were speed density fuel compensated. and most H.O. were mass air compensated 89-up. if your interested in mild to moderate+ eng enhancments the mass air flow setup is the way to go
Wrong, 302s in the F-series became SEFI MAF in 1994 when the 4R70W was introduced in them. Thankfully the AOD finally went away.
Next, the 302 truck was 185hp/270tq in the flat tappet version. My '88 F150 (302/AOD) has a roller block from the factory, just the nubs to hold the spider tray were not threaded.
You can do PLENTY with speed density, I have taken vehicles back to SD as MAF hits a limit with airflow. My Gen III GM truck is one with an STS butt-turbo, MAF simply was a limit at big HP. SD is just simply manifold pressure based. Easy as hell to tune with TwEECer or EECtuner type of units for Ford.
The EEC IVs for these trucks just need high manifold vacuum to operate. Small port heads (150-180cc max on a street 302 in a truck), the Edelbrock truck intake, mild cam, etc will be more than fine on the stock unit. OBVIOUSLY a custom chip is ideal as the stock truck EEC IV leaves some to be desired for max RPM, timing advance, etc.
I sure as hell wouldn't pay $500 for a 302HO, I bought one for $90 a few years back with 97k miles. The TQ/RV cam isn't that great, they're usually 204/214 .440" 112LSA style units. HO cam is in the 210/210 .444" 115.5LSA... basically the HO cam is not a bad grind with some 1.7:1 roller rockers to get the lift up a tad and a bit more duration.
Yes, Mustang shorty headers fit. I ran them before I went to Hookers... then I went to Thorley TriYs. The Stang shorty headers require a new Y pipe... if you're going through that hassle, just go long tubes. BIG gains in torque.
And a motor with a 3" stroke does not belong in a 3/4 ton truck. I'd swap in a 4.9 for a tow pig or a 351W.
Since you're pressed for time, I can see a used 302 HO for now then build a 408W. Stay away from garbage made in China cranks, if you can't afford to do it right... stick with the stock 3.5" crank turned .010", resize the 5.955" stock rods (they're forged already), get some decent SpeedPro forged slugs, and spend your money on heads.
Ford has never made some good heads from the factory. I have some TFS heads atop my F150, the difference in performance from the junk E7TEs is just insane. The spare sets I pulled off my other motors I use for wheel chocks.