How Hard Is it to swap a 351 to a 390
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J&SBroncolvrs
New member
it's difficult. Better of going for a 385 series engine like a 460 or 429. the engine perches are different and the bell housing for the transmission are different on a 390. Much more economical to put in a 460. or just turn the 351 back into a 400, zero the timing gears, put a cam in it and some high comp pistons with a 4 barrel intake and you have 300hp with 450 ft/lbs of torque. Makes a real monster out of the 400.
Johnny Reb
New member
yOU CAN GO TO MY ARTICLE ON SWAPING A 351-TO A 390. The wireing was no trouble. I uesd a point distributor . The motor mout towers-has to have the holes re-drilled on top for the motor mout to lay down in. You will need the clutch ord assembly from the frame to the motor block,a (352,360.,390. or 428 bellhouseing ). I also went with the 4 row radiator for extra cooling,the 390 clutch,throw out bearing,pilot bearing,. I f you have all the manual stuff on the 390-go for it. In a 4 wheel drive full time . You will get about 13 mpg(with a 2 barrel carb) You have plenty of room to work with. The cost of a 352 family(352,360,390, and 428) are cheaper. When you go to alot of power-you will have to go to stronger axles,and a few other things---if you have a 390 go for it. Their good engines.
Johnny Reb
New member
The 78 bronco that I put the 390 in had a 351 -with a 4 speed transmission. You did not have to do anything with the transmission. It stayed in place.If you should have any more questions on this swap-feel free to e-mail me.If you live in West Virginia close buy. I will show you it is a simple swap. Great for a beginner. The 390 has quite a bit of power also. Beside ,the price you have to pay for a sppeding ticket now days. You have to watch where you open it up.Good luck
J&SBroncolvrs
New member
I used a Comp cam 260H which can be used with the stock springs. the DEH cams are popular too, like a 256DEH from comp cams.
Johnny sounds like he knows what he is talking about though, if you have a 390 around that would be a cool swap!
Johnny Reb
New member
Thanks J&S. I have been out of the ball game for awhile. ,but I am getting back into it. The swap was easy for me. Later on when it gets nice out. I will take some pictures and try to get them posted on hear. He never said if he had a standard transmission or automatic-which he will have to figure up the cost on BOTH engines. You are assumeing(I believe) he was talking about a engine swap with a auto matic.I do believe the automatic for the 429-460 has the one piece alumnium case ----the same as a 390 automatic. Now it has been about 20 years since I rebuilt the 390 in my brothers 76 4x4 Ford pick-up(which had a automatic also. Now my bronco-that I put the 390 in has and had a 4 speed transmission. I have another 78 bronco that hsa the automatic transmission with a 400 engine. I am thinking of putting in a 300 -6 cylinder ,BUT-I am going for cost wise on both engines and fuel economy---I am tired of getting about 6 mpg in it(haha) If I put in the 300 I will post the details on hear.Again ,thank you and take care,Johnny
it has the c6 automatic but ive had bout half and half of the people telling me im gunna have to change trannys and all that other jazz but i have a 74 f250 with a 390 so i have everything i need the only prob is than the 250 has a 4 speed nd my bronco has a auto but my dad has a tranny if i have to swap them but i think i have everything unless theres somethin idk bout
American Thunder
New member
If I recall, the 390 uses the same frame mounts as the 300 inline 6. So finding mounts shouldnt be too tough. If you're going through the trouble of swapping in an FE, you might as well go with the King of FE torque, and use a 428 rotating assembly in that 390.
428 cubic inches of FE mass would definitely give you some extra passing power.
/emoticons/[email protected] 2x" width="20" height="20" />
428 cubic inches of FE mass would definitely give you some extra passing power.
/emoticons/[email protected] 2x" width="20" height="20" />Johnny Reb
New member
The 390 --I took it out of a 74 king cab ford. It had a 4speed trandsmission. The only thing you will need is to drill your holes for the 390 motor mounts -on top of the frame mount that is in your vehicle. Use the 390 bellhouseing and the clutch set up from your other truck-includeing the rod that goes from the frame(under the hood --near your steering column and it will go right in. If you should have any questions-please feel free to e-mail me at [email protected]. ----It is a realy easy job. Everything is easy to get to. Good luck and I hope to hear from you on this job
Johnny Reb
New member
I had a 428 and blew it up.--I would much rather have a 352-or a 390 because the cylinder wall is thicker . The 428 has a real thin cylinder wall. If you need torque in rough country---the 352 and 390 has plenty. Mysel;f ,when I buld something-I like for it to last for awhile and to me---thin cylinder walls isn,t for me. **** if you want more torque---------grab another gear :lol:
American Thunder
New member
I wasnt aware that any FE had thin cylinder walls.
Johnny Reb
New member
well I found out the hard way. Too much booze and I wasn,t watching the tach. I blew it at 115--drifting. The next day I tore it down the next day and couldn,t believe hopw thin it was. Then I put a 289 in and it has taken more punnishment ,easier on gas
and the parts are alot cheaper. Also if you are thinking about a 460--it is the same block as the 429-----but it is also bored out. I do not know the thickness of its cylinder wall.
I had a 429 that I traded for a 300 -6 cylinder-that I am planning on putting in one of my broncos
American Thunder
New member
The 429 and 460 both have a 4.36" bore and identical blocks, but the 429 has a 3.59" stroke, and the 460 has a 3.85" stroke.
I love the 289/302, it's one of the best engines ever built, and certainly one of the toughest. The one in my Mustang is bored and stroked to 332 cubes, and it can take some punishment, too. /emoticons/[email protected] 2x" width="20" height="20" />
http://videos.streetfire.net/video/BURNOUT...ng-II_11661.htm
http://videos.streetfire.net/video/530-hp-...-mph_194208.htm
I also have a 300 inline, the one I put in my '83 Bronc is out of a '95 F150, but I converted it to carb, and a points distributor.
I love the 289/302, it's one of the best engines ever built, and certainly one of the toughest. The one in my Mustang is bored and stroked to 332 cubes, and it can take some punishment, too.
/emoticons/[email protected] 2x" width="20" height="20" />http://videos.streetfire.net/video/BURNOUT...ng-II_11661.htm
http://videos.streetfire.net/video/530-hp-...-mph_194208.htm
I also have a 300 inline, the one I put in my '83 Bronc is out of a '95 F150, but I converted it to carb, and a points distributor.
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Johnny Reb
New member
The 300 I traded for is a carb. I did not want the fuel injection because it is harder on gas. So I have heard. I know the carb -300 is easy on gas and yes-the 289 is a great engine--------also the 292-Y BLOCK is another great mnotor and easy on gas. My old 64 gets about 23 mpgThe 429 and 460 both have a 4.36" bore and identical blocks, but the 429 has a 3.59" stroke, and the 460 has a 3.85" stroke.
I love the 289/302, it's one of the best engines ever built, and certainly one of the toughest. The one in my Mustang is bored and stroked to 332 cubes, and it can take some punishment, too.
http://videos.streetfire.net/video/BURNOUT...ng-II_11661.htm
http://videos.streetfire.net/video/530-hp-...-mph_194208.htm
I also have a 300 inline, the one I put in my '83 Bronc is out of a '95 F150, but I converted it to carb, and a points distributor.
I have about 6 or 7--- 390,s lieing aroud hear
, a couple of 289,s.
Johnny Reb
New member
What kind of gears do you have in the bronco with the 300 -6. ? I am thinking about putting one in my 78.The 429 and 460 both have a 4.36" bore and identical blocks, but the 429 has a 3.59" stroke, and the 460 has a 3.85" stroke.
I love the 289/302, it's one of the best engines ever built, and certainly one of the toughest. The one in my Mustang is bored and stroked to 332 cubes, and it can take some punishment, too.
http://videos.streetfire.net/video/BURNOUT...ng-II_11661.htm
http://videos.streetfire.net/video/530-hp-...-mph_194208.htm
I also have a 300 inline, the one I put in my '83 Bronc is out of a '95 F150, but I converted it to carb, and a points distributor.
Was their alot of trouble putting it in and I will be useing a point distributor out of an older model. I do not like the looks of the big bulky looking distributor. It has a 400 in it now,but I will be holding onto the 400 for later use and it will give me something to do when I rebuild it
American Thunder
New member
The injected motors have a "fast burn" head, so it's difficult to get the timing correct without the computer running it. I'm only running 22 degrees total timing on my '95 motor, otherwise, it will ping. These heads are more efficient than the older heads, and the injected motor has 9:1 compression, too. Also, the fuel injected 300 has dual exhaust manifolds, which flow a lot better than the old log type manifolds.
My '83 with the stock 3.55 gears and the 5-speed I swapped in, averages 22 mpg, and I can stay in overdrive even up hills, so it was worth the effort I put into it.
Eventually, I'm going to buy a 240 head with 9.25:1 compression, port it, upgrade it to 1.94" and 1.6" ss valves, a CC mild camshaft, offy DP intake, and a holley 450 4bbl carb. That combination yields 230-250 hp and 310 ft/lbs of torque without hurting cruising mileage, and it will outpull a 351.
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