Topic: 1966 5.0 L swap trouble

[Dctorflgood]

Me and my brother finished building a '81 5.0 engine up for our 66 and finally got it sitting in the bay.  Weve got full length headers that we can see will obviously not fit.  Will any full length headers fit or will we have to pick up some shortys? Either way, which does everyone recomend? Thanks  a lot.

[Soaring]

The 5.0 is too big of an engine to put in a 66 and expect to add long tube headers.  They just don't fit in that tiny compartment.  You might try to use some shorties, but I doubt they will fit either.  Welcome to to the site.  Glad to have you here. 

[BlackShadow]

The 302 = 5.0liter will fit it the same block as many 289. What are the header hitting the Z-bar or something else? Tri y header long tube should fit. There should be other makes of header too. I know Hedman makes a long tube header to fit. Take a look at Summit Race.

[Dctorflgood]

We've got full length Flowtech headers from Summit, part BIG-12102FLT .  They say they'll fit '64-'70 with a 5.0, but not with a c-6 trans.  We're using an AOD tranny, which doesnt seem like there would be any problems with that.  The area we're running into clearance issues is the inside of the strut tower.  We havent put in a HUGE effort to put them in, the just really dont look like they'll work.   On my last '66 Mustang we put some full length Hedman headers on the 289, so we're just at a loss at what we need or need to do. Thanks everyone for the welcome and responses!

[Soaring]

You may have to chink out some of the headers to make them work,  but they were not intended to fit in that tiny space.  I know.  I'm an old fuddy duddy, but maybe you could try some shorties.  Long tubes will fit if you massage the engine bay and shock towers, but that's a lot of trouble and expense. 

[BlackShadow]

You don't need to chink out some of the headers to make them work or massage the engine bay and shock towers. And short tube header are the waste of money performance wise  you might as will just install the K code 289 hipo exhaust manifolds. If you were putting in a 5.8L  I would say sure the shortie would work . But the 5.0 is the same motor size wise as the 289 so I know there are  header out there which will fit. I have tri y and I did nothing but installed them with the motor out of the car and drop it in. No problem with shock towers, or engine bay trouble. Just find header to fit a 1965-66 mustang 289 and they will work.  I would suggest you install them out side of the engine bay and then drop the motor in. Sometime the the Z-bar get in the way but your installing a auto so shouldn't  be a problem there.

[Dctorflgood]

Thanks Black, I always heard that the 5.0 was the same size as the 289, i was getting pretty worried hearing that a 5.0 is too big for a 66.  We tried dropping the engine in with the headers and tranny on, but we couldnt get it in there.  The headers on both sides kept jamming in between the bay.  Do you remember where you got your set of tri ys? Thanks again

[BlackShadow]

I would have to go back and look  but I buy most of my parts  from Mustangs Plus or Mustangs Unlimited.  Mustangs Plus is very good about knowing what works with restos. Try calling them 1 800 999 4289  they are in Stockton CA

[TexasAxMan]

I got my tri-y's from Sacremento Mustang (but through eBay) for $229 shipped.  They fit with no clearancing and I didn't even scratch them getting them in.  They are a chrome (or polished, not sure) finish, so not as good as ceramic coated, but for the price I don't think you can beat them.