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Topic: GT40/Explorer 302 into T-bird project (Read 2508 times) previous topic - next topic

GT40/Explorer 302 into T-bird project

Most of ya know I've been blessed with a Gt40/Explorer engine, and I've been working 3 days *more like evenings* a week on it.:flip: I've had a few problems but I think I got 'em covered. I've torn apart the GT40 engine, and have one side of the SO 302 *it's not a 308 :yuck: * I've found out it has stock pistons: like maybe a .030 dish? So instead of rebuilding my SO engine to work with the Gt40 heads, I've decided to go with the explorer 302...ONE question though...Will the Explorer engine support a bigger cam? It has vavle reliefs in it ect. i'll probably redo the rings, and bearings in the explorer engine...you know freshen it up a bit...might put in Cobra roller rockers...also not sure of the rocker ratio in the explorer.
'83 Cougar *the never ending project* warmed over 306 v8,c4,8.8 posi with 5 lug conversion
'91 mustang strictly street-in progress
'00 f150 7700-Mean Green: jet stage 1 chip,ported upper intake with 1" spacer,'04 Super Duty intake with injectors,summit racing short tube headers with true 2.5" duals with smithy's glasspacks!

GT40/Explorer 302 into T-bird project

Reply #1
yep i have a gt40p engine in my t-bird, i have a motorsports b cam, edelbrock intake and 24lb injectors
95 Ranger Splash 2.3
88 Tbird Sport :ies::ies:
5.0 SO, stainless shorty headers, w/ Magnaflow lers. KYB struts, KYB shocks. 5lug conversion from sn95 Mustang, subframe connectors, drilled and slotted rotors, 03 Mach 1 wheels. sequential taillights.140 speedo

GT40/Explorer 302 into T-bird project

Reply #2
What kind of headers are you guys running?

GT40/Explorer 302 into T-bird project

Reply #3
I'm running BBK shortys on the Cougar, the Tbird had Heddman long tubes. You just have to use wires with 90 deg. boots on the plug end.:D
95 Ranger Splash 2.3
88 Tbird Sport :ies::ies:
5.0 SO, stainless shorty headers, w/ Magnaflow lers. KYB struts, KYB shocks. 5lug conversion from sn95 Mustang, subframe connectors, drilled and slotted rotors, 03 Mach 1 wheels. sequential taillights.140 speedo

GT40/Explorer 302 into T-bird project

Reply #4
what all has to be done to an exploder 5.0 to put it in a Tbird, besides the oil pan, and the timing cover?
could the explorer harness be made to work with an '88 body harness?
'98 Explorer 5.0
'20 Malibu (I know, Chevy, but, 35MPG. Let's go brandon, eh)

GT40/Explorer 302 into T-bird project

Reply #5
Quote from: ThunderbirdSport302;76622
what all has to be done to an exploder 5.0 to put it in a Tbird, besides the oil pan, and the timing cover?
could the explorer harness be made to work with an '88 body harness?

Hey Sport,  did you ever get an answer to this question?  I have a line on a 1998 explorer engine and was wondering if it made sense to drop it in my bird instead of changing heads, intakes, injectors and cams. 

What about the EEC?  do we need the one from the explorer?
'88 Bird 5.0, TW 170s, HO cam, Scorpion rockers, Explorer intake 70mm TB/EGR, MAF conversion, 24# injectors, 8.8 3.73 disc rear end swap, console swap, leather seats, 11" front discs, 15-1 rack, TC springs all around, x-pipe, BBK headers,  welded sub-frame, unlocked digital speedo.

GT40/Explorer 302 into T-bird project

Reply #6
Beat to death subject by now.
You get your Explorer engine, you reuse your SO oil pan, oil pickup, timing cover, accessories, and fuel rails.  You may also want to reuse the coolant tubing that runs along the bank 1 side of the intake.  You'll need to drill and tap intake runner no.5 to install your air charge temp sensor (you DO NOT want to install it anywhere else), and if you want to use the egr cooler, you'll need to drill and tap the coolant passage in the bank 1 side of the lower intake at the rear.  This is also a really good time to think about swapping the cam, as the Explorer cam is useless.  An HO cam goes nicely with the combo.  You have to remove the cam sensor and replace it with your SO distributor (change plug wires to HO firing order).  You may also want to remove the oil cooler from the Explorer engine and install a standard hollow threaded insert for mounting your oil filter (or you may want to keep the cooler and fabricate a new lower rad hose and water pump inlet hose elbow) 

For reference, 96 and early 97 engines will have GT40 heads with larger intake valves and a standard spark plug angle, they will also have internal EGR (like your SO) which will allow you to keep EGR functions working.
Late 97 and on will have GT40P heads.  You MAY need special headers, and you will probably lose EGR function.  I used a 96 engine, it made my life easier.  I may have forgotten 1 or 2 things, but you'll figure it out.  It's not brain surgery.

GT40/Explorer 302 into T-bird project

Reply #7
Quote from: TheFoeYouKnow;432163
Beat to death subject by now.
You get your Explorer engine, you reuse your SO oil pan, oil pickup, timing cover, accessories, and fuel rails.  You may also want to reuse the coolant tubing that runs along the bank 1 side of the intake.  You'll need to drill and tap intake runner no.5 to install your air charge temp sensor (you DO NOT want to install it anywhere else), and if you want to use the egr cooler, you'll need to drill and tap the coolant passage in the bank 1 side of the lower intake at the rear.  This is also a really good time to think about swapping the cam, as the Explorer cam is useless.  An HO cam goes nicely with the combo.  You have to remove the cam sensor and replace it with your SO distributor (change plug wires to HO firing order).  You may also want to remove the oil cooler from the Explorer engine and install a standard hollow threaded insert for mounting your oil filter (or you may want to keep the cooler and fabricate a new lower rad hose and water pump inlet hose elbow) 

For reference, 96 and early 97 engines will have GT40 heads with larger intake valves and a standard spark plug angle, they will also have internal EGR (like your SO) which will allow you to keep EGR functions working.
Late 97 and on will have GT40P heads.  You MAY need special headers, and you will probably lose EGR function.  I used a 96 engine, it made my life easier.  I may have forgotten 1 or 2 things, but you'll figure it out.  It's not brain surgery.


thanks Foe! I guess the 98 engine isn't ideal then.  what about the EEC?  Do you use the one from the Explorer or ?    Is the swap worth the pain/expense or is better just to build out the SO motor?
'88 Bird 5.0, TW 170s, HO cam, Scorpion rockers, Explorer intake 70mm TB/EGR, MAF conversion, 24# injectors, 8.8 3.73 disc rear end swap, console swap, leather seats, 11" front discs, 15-1 rack, TC springs all around, x-pipe, BBK headers,  welded sub-frame, unlocked digital speedo.


GT40/Explorer 302 into T-bird project

Reply #9
The Explorer EEC is OBD-II, while our cars were OBD-1. In other words, no, the Explorer EEC won't work.

If you do use the Explorer engine, make sure to put an HO cam into it first...the stock Explorer will work, but the HO will raise the power band a bit. Better yet, use an aftermarket cam if you want to make great than stock power. The TFS-1 cam is pretty popular in a gt-40 5.0...

I'd forgotten all about this thread...man, I really didn't know doodly about GT40 heads and engines back then lol.

You can also use the explorer throttle body, it's an upgrade over the HO unit, but you'll need to modify it a bit. As long as you have either your stock 5.0 TB, or one from an HO, that's all you need. There's directions all over the net, a google search will tell you exactly how.I'm not being short with ya, I just can't remember off the top of my head :D
'98 Explorer 5.0
'20 Malibu (I know, Chevy, but, 35MPG. Let's go brandon, eh)

GT40/Explorer 302 into T-bird project

Reply #10
Just to clear up the valve size:

GT40 head: 1.84" inatke/1.54" exhaust
GT40P head: 1.84" intake/1.46" exhaust

Supposedly the 1.46" exhaust valve in the GT40P head (same size as the E6/E7 head) flows just like the 1.54" valve in the GT40 head due to the exhaust port design.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

GT40/Explorer 302 into T-bird project

Reply #11
My bad, I haven't looked at it since I did the swap in mine almost 2 years ago.  I still like the 3-bar head better.  I don't even have them anymore, though.

None the less, P or non-P, the GT40 Explorer engine is superior as a shallow-end swap.  As far as I know, it doesn't have the forged pistons the HO has, but it's pistons are at least hypereutectic, while the SO pistons are simply plain cast aluminum.  The Explorer also has the F1SE block which has thicker cylinder walls.

GT40/Explorer 302 into T-bird project

Reply #12
Quote from: TheFoeYouKnow;432211
My bad, I haven't looked at it since I did the swap in mine almost 2 years ago.  I still like the 3-bar head better.  I don't even have them anymore, though.

None the less, P or non-P, the GT40 Explorer engine is superior as a shallow-end swap.  As far as I know, it doesn't have the forged pistons the HO has, but it's pistons are at least hypereutectic, while the SO pistons are simply plain cast aluminum.  The Explorer also has the F1SE block which has thicker cylinder walls.

Agreed. If one is doing a junkyard swap don't even waste the money on a straight HO swap. The GT40 swap costs the same. Just change the springs in the heads and drop in a HO cam. Easy 275-300hp.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.