well in my 1975 f150, the guy i got it from said the truck came with a 360 but it blew in 1983 so he got a donner engine from the junkyard and had forgeten if it was a 360 or a 390, well i was looking for 3"s on the block and i founf ont he passenger side D3TE my book says its a 390 made from either 73 to 76, and on the drivers side of the block there is a X ont he back and the book says that means heavy duty truck engine or racing engine, is there any other way to tell if its a 390 or is the #'s D3TE, correct for a 390 or were there other motors that were the same, thanks

 

You have a 4.05" bore block. That is all you can tell from the writings on it. You have to measure the stroke or get the casting number off of the crank.

 

so if i try the dowel test, 3.5 is a 360 and 3.78 is a 390 right

 

Yes, 3.5=360 and 3.78=390.

You can also ID the crank, but that's a bit harder if in the truck.

 

yes its in the truck but i want to find out if its a 360 or 390 because i am going to build up a 390 and put into it, so no matter what the engine is coming out, but if it is a 360 i will have to find a 390 and put that in the shop and work on it, so i want to find out now so i dont have to tear it out and have everything laying all over because i dont have the room in the shop to have it sitting very long, so im hopeing its a 390 so i can just take it out and build it up because i have a 4 barrell intake and carb and electronic ignition already so i hope i dont have to go searching for a 390 if its a 360, whats the cheapest mods i can do to the 390, its going in a 1975 f150 2x4 truck.

 

ok the guy a bought it from called me back and said he found the rebuild sheet, and it says its a 390 bored .30 over, so now i need to get it out of the truck take it apart, rering it, and more than likely rebearing it even tho that was done once in 92, and put in a crane 901 cam, stoc 4 barrell intake and carb off of a 352, electonic ignition, set of headman headers and i should be good to go what kinda hp do u think ill be running with that setup, thanks

 

How many miles since the rebuild? Have you done a compressoin check?

 

i am not sure on actual miles on the engine but sense the rebuild the last owner said 50,000 at the most. and i havnt done a compression test but i know there is a bent pushrod on the #7 cylinder and some valves are bad so thats why we are tearing it out to begin with, so i figured while its out it just as well have a fresh rebuild, rings and bearings.