429 thunderjet vs 390 hp

ethan_lanning · Post by **ethan_lanning** » January 11, 2011, 3:02 pm

Well I recently found someone with a 1968 thunderbird that has a 429 thunderjet that is stock and runs fine...so my question is shoud I try and buy the motor and put it in my truck or shoud I just stick with the mostly stock 390 gt that I have in it now...the truck is a f250 4x4 that I drive ocassionaly but mostly just drive in the snow and play in the mud...just lookin for some opinions

thanks

Jonas · Post by **Jonas** » January 11, 2011, 3:27 pm

I think the 429 would give you more horsepower. I have had both, but not a huge difference.

There would be considerable issues putting the 429 in your truck. You would need a find a transmission for it, or bellhousing if standard. Guessing being 4X4 that might be more difficult then two wheel drive. Not to mention mounting the motor. I am partial to FE's though.

I would not do it.

CoralRed · Post by **CoralRed** » January 11, 2011, 4:24 pm

X2 on the thumbs down. I just spent a small fortune on a similar swap- a 545 stroker into my 1966 F100. It's not just the motor: you have to consider all the other stuff- the tranny, the drive shaft mods, the radiator, the engine ancillaries, the starter...etc, etc.
If you want more power go to Reincarnation motors. Barry R. has some great mods for the 390 that should get you what you want.
If I had only known....
Hope this helps.

Gritsngumbo · Post by **Gritsngumbo** » January 11, 2011, 4:55 pm

CoralRed wrote:If you want more power go to Reincarnation motors. Barry R. has some great mods for the 390 that should get you what you want.

Sorry to jump in, but do you have a link or better contact info for Reincarnation Motors? I didn't find it in the "google". Thanks

BobbyFord · Post by **BobbyFord** » January 11, 2011, 5:59 pm

Here is the link to Scotty's shop: http://reincarnation-automotive.com/
But that is not where Barry is.
Barry is at Survival Motorsports: http://www.survivalmotorsports.com/
Scotty is more the 385 series guru, whereas Barry is more the FE guru.

banjopicker66 · Post by **banjopicker66** » January 11, 2011, 6:03 pm

I concur with leaving it an FE. I put a 460 in my Slick, and like it, but it meant changing the exhaust, motor mounts, engine perches, transmission, power steering and alternator. Not too bad if you have a '65/'66 and it is 2WD. Unless you have the complete engine front to back and top to bottom, it will give you a lot of grief.
Besides, since yours is a 4x4, the motor mounts would have to be aftermarket, and that is another fabrication job in itself. Also, assuming your Slick was FE equipped from the factory, the bell housing motor mounts will wreak havoc with the 385 exhaust.
Keep it FE is my advice.

Brian Taylor · Post by **Brian Taylor** » January 11, 2011, 6:51 pm

get a 460 stroker kit:
http://www.themustangdepot.com/servlet/ ... kit/Detail

qwertyd10n · Post by **qwertyd10n** » January 11, 2011, 8:38 pm

I'm going the stroked 390 route with my '66 F100 4x4. And I'd definitely recommend getting a hold of Barry at Survival. He helped me spec out my engine and really knows FE engines and what they can and can't do extremely well.

A few guys said I should just go with a 460, but that would have been a LOT more work as the other guys have indicated.

As it stands, I'll have 445 cubic inches under the hood when I'm done and probably be pushing 500hp and over 500 ft lbs of torque.

Cheers,
Dion

rick heisler · Post by **rick heisler** » January 11, 2011, 9:04 pm

I put the same motor in my 64 4b4 had no problems doing it and i had a devorced transfercace u wont get nere the power from the 390 as 429 stock check the heads if thier dove heads ull have all the power u want.U only live once and the swap is easy even for a basic machnic

CoralRed · Post by **CoralRed** » January 11, 2011, 9:23 pm

Thanks for the correction, Bobbyford. I mixed up the names for Scotty's and Barry's shops. Hey Dion, we still have to get together. I'd love to see your truck, and of course you're welcome to check mine out as well!
For those who are interested, I believe Barry has published a new book on the 390 as well. It's called How to Build Max-Performance Ford FE Engines by Barry Rabotnick and is available at Survival or through Amazon.

Good luck with your motor!

qwertyd10n · Post by **qwertyd10n** » January 11, 2011, 10:15 pm

Hey Mike, we should definitely get together sometime.

I've actually got a copy of Barry's new book - great resource!

Cheers,
Dion

66camperspecial · Post by **66camperspecial** » January 12, 2011, 10:42 pm

I think those motors have 10 or 10.5 compression so they will like good gas.

Effie · Post by **Effie** » January 15, 2011, 9:23 am

66camperspecial wrote:I think those motors have 10 or 10.5 compression so they will like good gas.

Correct, that '68 has the high compression heads. Very sought after for the 429/460 because they were only used for three years - '68/69/70.

I have that same exact engine in my Bronco, the '68 429 t-jet. I have to run 93 in it, and that's with the timing cut back. Its a gas hog, but a lot of fun to drive.

BUT...as far as the swap goes, I'd stick with the 390 FE because that's what you've already got and like was said, I'm partial to the FE myself, even though I have both.

66camperspecial · Post by **66camperspecial** » January 15, 2011, 10:03 am

I put a rebuilt mid 70s 460 in my 66 and it has much more power and if I keep my foot out of it will get better gas mileage then with the original 352,I did not go through the motor and think it has a non stock cam. Went from 4.10 to 3.54 gears and the gas mileage did not change with the 352 but the 460 has much more torque and moves it much more easily and suprised me with better gas mileage.

ABA · Post by **ABA** » January 15, 2011, 10:23 am

Run the 390 till it dies and have the 429 ready when it does.

My driver at the moment has a 352 and it don't come close to the 460 torque monster it replaced.
Can't wait to get my 429 on the road.

64 f100 · Post by **64 f100** » January 16, 2011, 1:13 pm

Lots of pro's and cons either way. From the standpoint of what you already have as to what you would pay to make the change, fairly certain it may not be worth it. to build 385 engine right, you need to do some research. I had one with the Dove heads and with a 460 it was the wrong way to go, because of the gas issue. The real way to be able to run poorer grade of gas is the quench , and to get that you need to deck the block so your really need the later heads to keep compression down . this is to prevent spark knock, and get the power and performance you want. Building either engine costs a lot o=f money, if you do it right. With the 385 you may get more power but a lot more trouble and expense from the conversion. If, it were a 2 wheel drive not so much. Both engines are great , just a matter of what you want to build and where you want to be. To learn more go to the 460 engine site. Lots of info there.

Rich

62galxe · Post by **62galxe** » January 16, 2011, 4:42 pm

You can use the early heads with a dished piston to lower compression.