Engine What mods can I make to a 5.0

Exrace89GT

Member
Mar 29, 2019
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Lompoc, CA
For you all that live in California. What mods can I make to my ‘89 5.0 and keep it smog legal? It’s a GT 5-speed. Is any of the letter cams legal? Can I use Explorer heads and intake? Aftermarket parts? I’m rebuilding the engine, so it will be 30 over bore and a 10-10 crank.Thanks
 
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I’m not from Cali, but am very aware of what the laws regarding “legal” mod’s are in the area. Laws are close to the same in Mass...
You can go for a very strong build, if so desired. Supercharger, Twisted Wedge Heads, the best engine build for the buck, & legal, IMO, it the TrickFlow Top end kit. 360/350B. 2.02/1.60 170cc Intake port Assembled Heads, Track heat upper/Lower, Stage 1 Cam, Rockers, Pushrods, Locking Stud Nots.Studs/Guideplates, Gaskets, ARP Head Bolts. Gets you to about 315RWHP/330Ft/Lbs Tq. Accepts all your Smog, 50 State Legal. Strong, nice idle lope, Dynoed at 360HP.(Gross).
You need #24 Injectors, 70-75mm TB, CAI Intake, MAF Calibrated to 24lb Injectors. Headers/Exhaust.About 3,800$ for all. Too steep?.
As long as you’re not planning on removing your SMOG equipment, you’ll have no issues. The Explorer’s GT40/GT40P heads can absolutely be run, setup with new Springs, Retainers, keepers,Screw in Studs are much preferred, Viton Valve seals. More power with a Dual Pattern Cam from Comp Cams, 270HR or 274 from C.Cams, TrickFlow Stage 1 HE Cam, 2,000-5,500- pulls to 6,000, you could run a Supercharger if so desires. MFG advertises legality, you get a waiver Sticker,& they can’t bother you.
Gears are a great mod. 3.73’s, inexpensive. A cool air Intage, 70mm TB, Headers (Shorty’s are legal, LT’s are usually not). Buy parts slow you’ll need later, anyways. A 4 Bank Chip, you can switch back to stock, Car will run fine with a mild build, BAMA makes legal Tunes, too.
GT40P Heads accepts EGR, AIR injection from Smog pump, ported Lower, Cobra upper, Injectors, CAI, 24’s, Tune, exhaust, get you 260-275RWHP, What’s your Budget?
 
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I’m not from Cali, but am very aware of what the laws regarding “legal” mod’s are in the area. Laws are close to the same in Mass...

Except they don't pop hoods and verify components in MA. As long as the car isn't too loud, a lot of stuff will fly under the radar with pre-obd2 cars.
 
Except they don't pop hoods and verify components in MA. As long as the car isn't too loud, a lot of stuff will fly under the radar with pre-obd2 cars.
OBD-1’s are easier, as texted “under the radar”. Pop Hoods & verify in Ma.? They can, and may. A strongly built Cali.Legal OBD-2 Car seems likely better off bought, than built, Monetarily..