Skip to main content
Topic: 302 or 351 into 87 3.8 (Read 3322 times) previous topic - next topic

302 or 351 into 87 3.8

I'm thinking about replacing my current 3.8 with a carbed 302 or 351.  I know...i know... FI is the way to go.  I'm kind of old school, and some of the FI related parts aren't exactly easy to find.  Initially, I'd like to keep the original automatic transmission until I could afford to upgrade to something a little stronger. 

I've done some searching and keep seeing 'wiring' as one of the challenges I'd run into.  Can somebody give me an idea what sort of wiring changes I may be in for?

302 or 351 into 87 3.8

Reply #1
I am thinking along the same lines as you. I get brain numb thinking of all the wire harness ect that goes with FI. As far as trany I think I will swap the C5 out with a C4. Seems to be more perforamce parts for C4 over a C5.

302 or 351 into 87 3.8

Reply #2
The wiring isn't all that bad.  The harness disconnects from the firewall at the salt and pepper shakers.  Autozone has most of the schematics for what you need to do.

If you go 351 EFI, you can get a Pickup truck lower, and use your 5.0 upper with an adapter from BC Broncos.  Not sure if it will fit under a stock hood.  I would suspect no.

The C5 descended from the C4.  C4 has been around since the mid 60s and was the transmission of choice behind most medium duty engines in the ford fleet mid 60s-mid 70s.  The later70s C4s are popular in the racing community for its relatively light weight, low drag, and simple design.  Hence the huge after-market support for the C4. 

I would pick a trans on your driving habits.  If you plan to daily drive the car and you do any amount of freeway driving, you should look for an AOD or a 5spd.  I have heard that T-5s are borderline with a 351.  You could pick up an AOD from a 92 or earlier supercoupe for a good tough trans.  Rebuilds, especially good ones, can be very pricy.  I have seen quotes for a stock rebuild that exceed a Lentech trans.

If you just tool side streets or Its just a weekend warrior, you can get a built c4 pretty inexpensively (or even build it yourself).  You could go C6 but only if you plan to really make some serious power.  Otherwise it will probably just slow you down.

Remember, you will need exhaust manifolds and probably a cowl hood to cram that 351w in there (with the efi and adapter).  You will also need a swap oil pan for a fox.
my $0.02.
My car is a gravity hybrid.  The gasoline engine gets me up the hills, and gravity gets me down.

302 or 351 into 87 3.8

Reply #3
To swap in an efi 5.0 (whether HO, or standard) is as simple as replacing the eec, and finding the same-year engine harness.

All plug and play. It's so simple it hurts to think about it, lol.

As far as the 351, you'll need a new pan, pickup, ignition setup, and you'll also have to figure out your TV cable for the transmission.

May as well figure on a set of Chuck's mounts, unless you can find the rare 5.0-FoxTbird/Cougar mount-to-engine brackets.
(Mustang stuff will NOT work for your year)

Myself, I'd find an '87 5.0 Bird or Cat for the harness, grab an HO and eec from a stang or linc markVII, and get busy.

The fuel lines will be the only hassle with this route, because the 3.8 lines come through the pass fender while the V8 cars have them through the bottom of the engine bay....there's a little fix to get around this though, 1WldBrd should be able to tell you, I think he did this a time or two..

Carburetors belong on lawn mowers and winston cup cars, because those goobers can't figure out a spark plug from a butt plug anyway, lol
'98 Explorer 5.0
'20 Malibu (I know, Chevy, but, 35MPG. Let's go brandon, eh)

302 or 351 into 87 3.8

Reply #4
We put a carbed 351W w/a C4 into our 88 TC and it turned out fine. Plus, with the stock 4 banger front springs, it had a nice rake to it. lol.

http://i244.photobucket.com/albums/gg4/flstci71/Car%20Pics/100_0167.jpg
1987 Turbo Coupe - Son's car
1987 Super Coupe - Son's project car
1934 Ford - My project car

302 or 351 into 87 3.8

Reply #5
I did a 5.8L efi swap into mine. I would go efi if I was you.
1988 Thunderbird Sport. Work in Progress
5.8L swap w/fitech efi, 4R70W swap w/quick 4 controller, 2003 GT rear diff, 5 Lug swap

Bought this car back as an old project car.

:burnout:

302 or 351 into 87 3.8

Reply #6
What intake did you use for the EFI?  I've been considering this for my 67 mustang.
My car is a gravity hybrid.  The gasoline engine gets me up the hills, and gravity gets me down.

302 or 351 into 87 3.8

Reply #7
Thanks all for your advice.  It sounds like going to a 5.0 EFI might not be as bad as I thought.  Decent motors are fairly easy to find around here, so I think I'll start by trying to locate a harness, then pick up a motor after that. 

An online search of Craigslist and some local yards didn't even produce an '87 bird or parts.  I get the feeling this is going to be an adventure.  If all else fails and I can't locate a harness (or can't find one that won't cost me a kidney), is there a 'suitable' substitute that would be close enough for me to modify?

302 or 351 into 87 3.8

Reply #8
If you're handy with electronics, you *could* adapt a Mustang harness, but I'd not recommend it.
Also try looking for the same year Cougar Xr7.

If worst case comes up, you can use an '88 harness, but you'll have to grab the connectors from each side, (engine and body harnesses) and repin all your wires into those.
'98 Explorer 5.0
'20 Malibu (I know, Chevy, but, 35MPG. Let's go brandon, eh)

302 or 351 into 87 3.8

Reply #9
I used the Professional Products knock off Edelbrock intake. 351w lower with the 5.0L upper.
1988 Thunderbird Sport. Work in Progress
5.8L swap w/fitech efi, 4R70W swap w/quick 4 controller, 2003 GT rear diff, 5 Lug swap

Bought this car back as an old project car.

:burnout: