351w in an 85 thunderbird

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Jan 29, 2003 | 11:17 AM

scott9320

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From: beverly, Ohio

351w in an 85 thunderbird

I'm gettin ready to put a 351w in an 85 t-bird. What I want to know is, are the bellhousing bolt pattern the same on both the 3.8 v-6 and the 351w. just wanting to know if I need to start looking for another tranny or just have this one built. Just realized that the tranny is a c-5

thanks
scott

Last edited by scott9320; Jan 29, 2003 at 11:52 AM.

Jan 29, 2003 | 12:42 PM

lvmoose007

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From: Oregon: Land of the Majes

351w in an 85 thunderbird

The C5 tranny behind the 3.8 will fit, but not hold up behind the 351. The internals are not set up for an engine that is approaching twice the power output, unless you granny drive it all of the time, and the reason for installing the 351 is to go fast. You can build a C4 for it really easily, or if you are interested, I can tell you what to look for in an AOD conversion......

Jan 29, 2003 | 12:44 PM

lvmoose007

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From: Oregon: Land of the Majes

351w in an 85 thunderbird

By the way, you will REALLY need to upgrade the brakes on that fox body before you do any big engine swaps, the brakes are too small for the V-6 as it is.....(switch to mustang 11 inch 5.0 discs, etc)

Jan 29, 2003 | 12:57 PM

scott9320

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From: beverly, Ohio

351w in an 85 thunderbird

thanks for the tip on the brakes, I,m open to all tips and suggestions. Does anyone know of any sites with info on this swap?

Jan 29, 2003 | 02:02 PM

lvmoose007

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From: Oregon: Land of the Majes

351w in an 85 thunderbird

do a search under thunderbird clubs.......such names as the TCCOA, (thunderbird and Cougar club of america, or is that TCA), anyway, the 351 swap is going to be a bit difficult. You will need mustang 5.0 PS and AC brackets, and then you will have to order the 5.8 PS plate from ford motorsport(Jegs or Summit). You will need to get a complete 5.0 mustang exhaust(you will lengthen it right before the mufflers, and requires a set of BBK 351 swap headers), fuel line replacement( the 3.8 line is too small), the front spindles, struts, calipers, pads and rotors from a 87-93 mustang 5.0, you will then need to upgrade to 15 inch 5.0 wheels(there is always a catch) because the 14 inchers will not fit the fronts. The rear end will need replacing to an 8.8 unit if you hot rod it any, the 7.5 willl not hold up. You will also need to get a/c lines from a 5.0 if you wish to retain a/c, the 3.8 equipment will not work.......there is more, so look at this and see if you still want to do it, and then write back...........oh, is this car fuel injected?

Jan 29, 2003 | 07:49 PM

scott9320

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From: beverly, Ohio

351w in an 85 thunderbird

I have a 351w HO from an 86 f-250 that I'm gonna rebuild for this car so it will be carbed. As far as all the hard work, the first time I stomp all over one of those little import tuners, that will be reward enough for me. My plans for this 351 is gonna finish with a comp ratio around 9.5, 600 cfm holley, P and P heads with 1.9 int. and 1.6 ex., comp cam, headers, and alot of other little goodies.

Jan 29, 2003 | 08:27 PM

lvmoose007

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From: Oregon: Land of the Majes

351w in an 85 thunderbird

DON'T USE STOCK HEADS!!!! By the time you get all of the work done(and have it done right!), you could have had a new set of roush 200 heads for not much more money, and a heck of a lot more power(efficient combustion chamber, better ports) I have used several sets of P&P'd stock heads, and wasted alot of money and effort, the new stuff is that much better.

If you are going to build a hot rod out of it, you will really need to put a mustang 5.0 or turbo coupe 8.8 rear end in it, the 7.5 will last about 10 minutes before blowing the gears out of it. You will also need some traction help, the fox body rear suspension is a joke for anything powerful in front of it.

You will need subframe connectors, as well, my last t-bird had a modified 302 in it, and it still flexed all over the place. There are several other things you will need to look at, if you want any of my advice, write back......if done right, you have the potential for a low-12 second car here, just follow my lead.....