Hi, No prob’s!
Yes, I’m the grand scheme of things, your 4.6L motor is over midline lifespan @ 180K, not excessively. i’d built the top end (PI) after compression & leak down, fuel pressure/flow testing, pull off a valve cover & look for caked on grit, if nasty- may need a rebuild based on negligent maintenance. Save for a Rev-X Tuner (W/free unlimited tunes for each mod you add for life.. as long as you own the car) /Cool air intake combo(C&L racer is the best, IMO. Airaids are good for +25HP~35HP w/a tune, too). @ A. Muscle- prices drop if you buy both simultaneously)).
Consider this..Gears:
1) 86’-93’s share the same 8.8” rear end. Gears are hands down the best bang for the buck. Run FRPP (Ford Racing; at LMR). Changing them requires the gearset, an installation kit, axle bearings & seals, a shop that’s specific to rebuilding transaxles& differentials. Cost is about 500-700$ installed & it’ll feel like a entirely different vehicle. 2.73’s or 3.27’s to 3.73’s or 4.10’s- wow!
Your car has 5 ratios, 1-4 for performance, normal driving, RACING. 5th generally economical. The 96’-04’ T-45’s had an identical gear ratio spread, 3.37, 1.99, 1.33, 1.00, and.....0.67.- the ‘highway gear’.. Most don’t use 5th when racing, unless highly modified. It’s like a brick in the wind tunnel, taking lots of HP/TQ to overcome wind co-efficiencies. (Reverse is usually the same ratio as 1st; T-45’s run 3.22, I think).
Look at an old Muncie, Toploader, etc, note 4th gear is 1:1 as is 4th in T-45’s, yet UNLIKE the T-45 & most late 70’s & up cars, no highway gear.
I sent you a link below, verify your tire size after you plug in car info, then the 1st-5th gear T-45 ratios listed above, find a ratio that best suits you. it’ll show speed at 5,000 in 1st, or what RPM’s you’ll cross the 1/4 mile in in 4th, it may also be used backwards by plugging different gears in it & what difference you’ll see at redline in each gear. Old method of seeking the best Cam app, motor build HP/Tq @ RPM’s & ratio’s to land in the right gears to rev to redline at the finish.
2) The 96’s rear end should have a plate hanging off it, letter (E) means it's a 3.27 axle ratio, traction lock, limited slip differential. (1) - 2.73 conventional, ( A ) - 2.73 or 3.08 traction lock , ( C ) 3.27 traction lock, limited slip.
Math, just in case....
Formula: Engine RPM x Rear Tire diameter
———————————————— = Gear ratio
MPH X 336
2) Locate & Build another later model (99’-04’ 4.6L PI motor) like you were with this one.You'll be able to run a low octane tune as it’s already setup with lower Comp.dished pistons. They didn’t just make these for Mustangs, Trucks, Police Interceptor Crown Vic’s(P71 code, I think). State Police Int’s may have miles- but highway miles & were aggressively maintained. The shop takes care of their end, at the same time, run this this one & the biggest obstacle is adding the Bolt-on’ss, add gears, Cool air, headers, get tuned & find out if how the car feels, and how far away you are from where you think a good balance is....Cars going to need all the exhaust & other work, so it’s balanced. You’ll start at 250+ HP, not need PI stuff, already there. Cams & airbox was different- but they made changes within the motor may be different,
Shop will hot tank block, cold tank measure things up, buy bolt-on parts so they’re not wasted- reused when this motor drops in. Use your same CPU.. Re-ring it after a torque plate home, bearings, rank polishing.
Reaching MUCH further, Did you realize you can run a DOHC head on certain year SOHC blocks & make it into a 32V motor? Takes a Lots of research & learning-.... You wanted a project to get deeper into this subject, nothing will beat the research it’ll take to get you there, as a first project....that’d be my choice. You’ll need to do a lot of research, start with the 96’-04 shop manual, and have at it. Tremendous resources online at your disposal,
Too much..!or sound like better, or a future goal that you COULD plan if just sticking to the existing block the shop verifies & squares up, hopefully a re-ring hone & standard size bearings, no align boring or big end rod resizing. That’s a component I’d replace- rods, you get it back all machined to fit, you have all spec’s & are armed with an engine assembly book, check, recheck, assemble.
Hi about an aluminum block 5.4L Ford racing or an older Tekskid block, 4.6l, 5.4L, weighing about 60% of the Cast iron counterparts? FRPP’s 1,100-1,500 HP capable, your 4.6l’s cast steel block is capable of 500HP, with the right components. This all played into the more recent Coyote block, which can handle near twice the 440HP the first 5.0’s put out..
Lots of options, if you’re looking for remembrance in 20yrs...”you guys remember that swap in that GT this guy made...wow”, you’re doing it for the wrong reason.. You should consider a good Tech school & pursue this interest, it’s lucrative if in the right spot, jump into the Service, work in a spot you enjoy, retire at 38, schools paid for, travel, start your own shop.
Can’t beat it! BTW, your question regarding Pistons...the 4.6L in the 96’-98’s had plattop pistons w/reliefs, the 99’-04’ pistons were dished. The drawback being higher compression with the small chambered PI heads, and you’ll need to run 91+ octane to avoid detonation with that higher compression.so you want less compression to avoid that. Which means running dished pistons to drop the ratio. Or, as suggested, another motor- 99’04’, already PI motors, with 9.25-9.5:1 compression. You can RUN the motor, it’ll ping with any significant timing added, possible detonation.
Good reads below on the modular motors:
https://www.diyford.com/4-6l-5-4l-ford-rebuild-cheat-sheet-selecting-parts/
-Good luck, something to think on...
-John