alright, i have a 1969 390 2x4 and i was thinking about putting maybe a 351 in it, there are more parts and easier parts to find for that motor, would the motor fit right in the old 390's spot, or would i have to make massive ajustments, if thats the case, is there maybe another kind of engine that would have a little bit more power and reliability that yal would recommend, i would like to have a pretty quick truck but im not looking for a dragster or anything

 

is fuel mileage a problem. if not a believe a 460 would fit in there with little to no mods. that has plenty of power. but the 351 would fit if you change the frame mounts to 351 frame mounts and either change the bell housing on the tranny to a small block brll if possible, or change the tranny all together to a big block bell tranny.

 

Well If you want to make good HP out of your 390? check out the article on the fe 390 at hotrod.com... type in the search box...FE Engine..and hit search.. this will bring it up!! 450 HP on pump gas aint Bad!! Good Luck!!

 

i thought to put a 460 in a 390's place you had to change motor mounts and for sure the bell-houseing, and there is nothing wrong with the 390 they can make great hp and for the 460 if your looking for gas milleage the 460 is out of the question the 390's arnt much better, a 351 isnt no powerhouse, but it sure is better on gas milleage.

 

alright, ill check out that article that seems like my best and cheapest bet, thanks

 

Keep in mind that as of most recently no one offers headers for the 351w in a 67-72. I think you would be better of just waking up that old 390. A good cam, some new timing chain and gears, aftermarket dual plane intake and 4bbl. carb and a good set of headers with duals. With that combination it will run right with the average 460 and may surprise you on fuel mileage too. If properly set up and tuned you could see 15. Oh and don't forget electronic ignition.

 

why wouldn't 302 headers work

 

i would say stick with the 390 and build that up, i think you would be quite happy with the results of what the 390 can do.

 

I will agree with everyone who says keep the 390 as it is one of the most relaible engines I or my dad has ever run, they are rock solid and with and aluminum intake a 390 is lighter than an all cast iron 351w
Just my 2 cents
Steve

 

I haven't actually tried to install them but others here who have say they won't. It is because the deck height on the 351 is taller which changes the position of the exhaust ports in relation to the chassis.

 

since yal just brought up headers, i have a statement for those, i bought some haeders for a 390 and what pissed me off is they will not fit, there is NO room for then, if you were to get any headers, you would have to get custom shortys, i was very frustrated to find out they wouldnt work, i just got my truck back yesterday from the shop i put it in and they showed me why they wouldnt fit, and said no headers would prob fit unless they were shortys, so if you were goin to buy headers that say they fit for the 390, unless they area shortys, dont waste your money

 

Well I guess if you have 390 truck headers you had better Hang on to them..... Mine have been on my 70 F250 for 33 years now!!

 

Is your truck a manual or an automatic? Also to you want it to be an auto or a manual?


I swapped a 351W into my old 2wd 76 f-100. it was an easy swap. I took a c4 tranny from a 302 and got motor mount perches for a 302 and put it all together then I put mac shortie headers for a mustang on it and they fit nicely. I built the motor fast and put a high stall converter in the c4 and the truck was FAST!!!!.


I have since taken the 351W out of the 2wd and sold that truck when I bought my 76 4x4. when I bought it, it had a 390 and a c6 in it. I had a bunch of the money in my windsor and my windsor ran better than the 390 (the 390 was also rebuilt when I got it and ran well but I guess it didn't have a radical enough cam to match the power of the 351w) So I traded the 390 to a friend for a np435 np205 and a new flywheel/clutch and pressure plate.

I had to buy 351M motor mounts and wield them into place as the bolt holes didn't match up and I had to get clutch linkage from a junkyard and modify it. The clutch linkage was the hardest part but all told it went smoothly and I would do it again in a hearbeat. I found a set of shortie headers on ebay that looked like they would fit with the clutch linkage and they did. I can't read the part number on them but I can read the name flotech.

the 4x4 isn't quite as fast as my old 2wd was but that makes sense as I now have taller tires and all the extra weight of the axle, t-case and the cast iton tranny but it does pretty well.


I know that this info is for a mid 70's but my 71 f-250 is very similar to my other trucks so I figured that a lot of the info may be usefull. I also find that the 351W is a lot easier to work on.

 

I have a 460/C6 combo going in my 1967 f100 2wd and let me tell you it is no direct swap by any means. Nearly everything has to be modified. engine stands, tranny crossmember had to be modified, diveshaft shortened, you can't run power steering (it won't clear exhaust manafolds or headers). But the torque this 460 should put out will make up for all the time and money put into it. (3 weeks in the shop and $2100 price includes engine and tranny) also the truck had a 351W/C4 combo that was mildly built up but these trucks need the torque of a big block to get them moving. the truck ran a 18.6 at the 1/4 mi. track weighing in at 4210 lbs.

 

i think im goin to just keep the 390, but im goin to place a 4 barrel card in it as soon as i find one