Engine swap

[Boon]

Say I was to buy a used cobra with a 302 in it, but I want a big block. How great of an undertaking is this? Say it already has a tremec t5 tranny. Would the shifter be in the same position with the big block? How much of a mess would the motor mounts be? Does FFR weld their mounts or are they bolted? If bolted, do their frames have multiple hole positions for different mounts?

[RACERAL]

You would have to take the body off. Cut off the SB motor mounts, call Factory 5 and get you to send you some BB mounts, get the measurments as to where they are located. You would alao have to take the trans tunnel aluminum off and rework the trans tail mounting location. Lotta work. OR you could buy Dave Smiths very own big block car and call it a day. You will also get more response at the two web sites dedicated to Factory 5 cars. Really you can find a BB car that is for sale a whole lot easier and cheaper.
You really don't have to take the body off, but it would make the job a whole lot easier.

[Boon]

Holy cow. Mabry Mill!! We lived about 20 miles north of it on the parkway. Love it there.

[JoeT]

I suggest thinking about how you're going to use your future car. If you just want the "bragging rights" of a big block, that's one thing. But I think you'll find the smallblock cars have plenty of power options without re-inventing the whole car

[wrench87]

I went from a 342 small block to a 445fe big block, it is not that big of a deal.
FFR sells a fe motormount kit that just bolts to the original pads, you have to purchase the big block headers, I had to shorten my drive shaft.
I originally had a fuel injected car I kept the same fuel pump in my fuel cell and installed a return style regulator and a 750 quick fuel carb, I already had 600 lb springs front and rear so i was already set up for the extra weight.
The tranny mount is the same if you have a mkIII or newer there are different holes for the tranny mount to bolt to as the motor will not sit in the same spot.

[Clois Harlan]

Not a big deal. If you have the body that would make it easier for sure but it is not manditory. I made the same swith 14 years ago and I don't think it was a big deal. Not sure you want the T5 in it though (might be a little weak). Everything wrench said is true (headers, driveshaft, motor mounts and springs) but if you are considering doing this you knew there would be some up charges. Another point you might want to look at is your radiator. Big blocks CAN run a little more heat than a small block depending on your bore. One of my first engines was bored .060 and I couldn't go thru a McDonalds without it getting hot. MY 428 was .030 and I never had an issue with it nor does my FE 427 which is bored .015 over. If you want to be happy with your ride be sure you spend your money in the right places. Good Luck with your decision.

Clois Harlan

P.S. you may also need to notch your frame slightly where your starter might come in contact with it on the passenger side.

[cycleguy55]

You could, of course, switch out the 302 for a small block 427 and make the whole process simpler.