360, 390, or?

[Jrod70250]

Hello,

I picked up a 1970, F250 a few weeks back. When I purchased it I wasn’t able to drive it and it was towed to my place. Now that it is here, I have started to address the necessities. I would really like to know what engine I have so I could purchase a new carburetor, current one is leaking fuel. I have driven it around the block once but it was only a mile or two.

My big question- is there another method to tell what engine I have? I have measured the stroke multiple times and keep coming to 4 inches. Was looking for a clear 3.5 or 3.78. The engine was rebuilt at one time and the guy I purchased it from was not the one who did any of the work. VIN said the original engine was a 360.

Let me know it the picture posts-

https://imageshack.com/i/poP1SJ6Oj

[DuckRyder]

Without disassembly there really isn’t much way to differentiate other than measuring the stroke.

4 inches (3.98 actually) would be a 428 crank, which could be a 410 or 428 depending on bore size.

What carb is on it, I would say it would be unlikely for someone to put a a 410, 428 or build one for it and then put the stock 2V carb on it, i suppose it is possible some one later switched it back.

Truly, it probably doesn’t much matter what engine size it is for purposes of changing the carb, lets just figure out what carb is on it and go from there.

Give us some pictures. If there is a metal tag on the carb with numbers or numbers stamped into the front of the choke horn give us those too.

A note on casting numbers and the FE. Casting numbers might tell you what it isn’t, but not what it is. “352” in the front of the block also doesn’t mean anything that will help you here.

[Jrod70250]

It currently has the remanufactured two barrel. It is a 1.21 so I intended to replace it with a 350CFM. Figured this would be good for a 360 but if the engine is truly larger, it might be light.

[My427stang]

Even a 352 likes a 500 cfm Holley to the tune of about 20 HP, if swapping, don't waste your time with the 350.

The truck looks nice, as said before, who knows what's in it, if your numbers are good, likely has a 3.98 stroke, that means 410 or 428. However, with your carb change, consider headers, 2.5 or larger duals with an X or H pipe, and a distributor recurve and a open element air cleaner, and it will feel like a hot rod. If its an auto, a shift kit gets you to a lot of fun, and you haven't spent a lot of dough. Even with a 360 I'd go that route

[FLASH 1]

drop the pan and get the crankshaft ID # to be 100% sure