360 to 390 Torque Build questions

[MurrayPro92]

Hey all. I am new to the world of building engines. I have a 1969 F350 with a 360 bone stock other than headers. I am wanting to build an engine for this truck. I have in my possession a 360 (or maybe 390 not sure) in a 1968 F100 that is locked up pretty good. Its my fault though, I left the carb and hood off for a year and it filled with water. I am hoping I can salvage this engine and build it up. If not I can get another block and start from there I guess.

The truck is a one ton dually and does haul and tow. I have a 4 speed in her now and currently have 4:10 rear gear. I have a later model rear axle and will swap to 3:73 or 3:55 rear gear not sure yet.

Anyways here is kinda what i want to build.
390 with iron heads. Good low end torque. 250 HP would be nice but more is always better. Would like a kinda lumpy cam. Aluminum intake (although I actually have an iron 4 barrel intake already laying around) with 4 barrel carb Maybe EFI later?? HEI. Headers.

Pretty simple I think. Being pretty new to this I am not sure what it would take to make some decent power but still have towing torque. Also not really sure what headers work with this. The ones I have now the previous owner cut the frame and mashed the headers to make them clear.

From what I understand the difference between a 360 and 390 is crank, rods, and pistons (I think)

Also would like to do something to boost oil pressure if possible.

I know this same post has probably been asked a million times on here, my apologies. If anyone has some good links to places with info that would be great. Thanks!!

[Ren]

Dump the FE. Go with a 351W.

[cpuchalski]

Keep the FE if you want some good torque. I just finished rebuilding a 390 for my 66 F250, but I don't have it in my truck yet.

I went with an RV cam, new pistons, header, decked the block to .010 and had new valves and hardened seats put in. I went with a Holley Street Dominator alum intake because I found one cheap. I've calculated at just over 9:1 compression ratio.

I've got 4.10 rear end and NP435 trans, so it will definitely haul. Highway RPMs were a little high when I ran the same setup with the original 352, but I still managed 13mpg on the road. I wouldn't go any lower than 3.73 rear end if you're planning to haul much with your 1 Ton.

Have fun - keep us posted on your project.

Corey

[tnlprt]

Build it to 68 GT specs ...335HP ...427LBFt of torque


390 car pistons with 1.77 compression height

2.09 intake valves
1.65 exhaust valves
in the heads of your choice
There is no difference other than exhaust bolt pattern,springs and retainers between the GT heads and regular 390 heads

428 CJ spec hydraulic cam

Headers with 2.5 inch exhaust

650 or 700 vacuum secondary holley carb

recurved dist with either a pertronics or a dura spark with a MSD box

Performer RPM or a street master or a Street dominator

Run all day long on 93 octane fuel

[My427stang]

Build it to 68 GT specs ...335HP ...427LBFt of torque


390 car pistons with 1.77 compression height

2.09 intake valves
1.65 exhaust valves
in the heads of your choice
There is no difference other than exhaust bolt pattern,springs and retainers between the GT heads and regular 390 heads

428 CJ spec hydraulic cam

Headers with 2.5 inch exhaust

650 or 700 vacuum secondary holley carb

recurved dist with either a pertronics or a dura spark with a MSD box

Performer RPM or a street master or a Street dominator

Run all day long on 93 octane fuel

All great advice and spot on...we had one almost identical in a 68 4x4, although back then, we just ran the S intake, ran great but the recommendation above would be better. Also note the distributor recurve and headers are the biggest benefit above along with piston choice.

I'll add one thing though, if you blueprint the motor, especially in terms of deck height, chamber size and head gasket choice to calculate ACTUAL compression ratio, not guesstimated, you likely could take that CJ cam and advance it 4-6 degrees which would raise vacuum and torque part throttle. I wouldn't do it without measuring, but it could make a significant difference in the low/mid range throttle response. I also think that this combo could run on 87-89 depending on the curve and where you ended up for quench and compression ratio.

One last comment, another great intake manifold would be the iron CJ intake for this build. Not real easy to find, and heavy as hell, but you'd have basically a CJ motor, down 40 cubes, but offset by a better advance curve and exhaust improvements that would almost get you back to CJ power.

[DuckRyder]

Build it to 68 GT specs ...335HP ...427LBFt of torque


390 car pistons with 1.77 compression height

2.09 intake valves
1.65 exhaust valves
in the heads of your choice
There is no difference other than exhaust bolt pattern,springs and retainers between the GT heads and regular 390 heads

428 CJ spec hydraulic cam

Headers with 2.5 inch exhaust

650 or 700 vacuum secondary holley carb

recurved dist with either a pertronics or a dura spark with a MSD box

Performer RPM or a street master or a Street dominator

Run all day long on 93 octane fuel

All great advice and spot on...we had one almost identical in a 68 4x4, although back then, we just ran the S intake, ran great but the recommendation above would be better. Also note the distributor recurve and headers are the biggest benefit above along with piston choice.

I'll add one thing though, if you blueprint the motor, especially in terms of deck height, chamber size and head gasket choice to calculate ACTUAL compression ratio, not guesstimated, you likely could take that CJ cam and advance it 4-6 degrees which would raise vacuum and torque part throttle. I wouldn't do it without measuring, but it could make a significant difference in the low/mid range throttle response. I also think that this combo could run on 87-89 depending on the curve and where you ended up for quench and compression ratio.

One last comment, another great intake manifold would be the iron CJ intake for this build. Not real easy to find, and heavy as hell, but you'd have basically a CJ motor, down 40 cubes, but offset by a better advance curve and exhaust improvements that would almost get you back to CJ power.

Agree.

351W isn't a good choice due to header availability.

You probably need to tear down the core engine and figure out what you have to work with. If you're looking for a block anyway you might be able to find a 428 or a truck block that will bore to 428 bore.

I've said it before and I'll say it again here, If I had to convert another 360 to 390 I wouldn't bother, I'd go straight to 410 or bigger, but If the other engine is in fact a 390 then you're good.

OH, and high torque build and "lumpy" cam are somewhat divergent goals.

[MurrayPro92]

Thanks yall!!!

[MadJoe]

Agree.

351W isn't a good choice due to header availability.

You probably need to tear down the core engine and figure out what you have to work with. If you're looking for a block anyway you might be able to find a 428 or a truck block that will bore to 428 bore.

I've said it before and I'll say it again here, If I had to convert another 360 to 390 I wouldn't bother, I'd go straight to 410 or bigger, but If the other engine is in fact a 390 then you're good.

OH, and high torque build and "lumpy" cam are somewhat divergent goals.

Wow, I hadn't realized the 410/390/360 all had the same bore. This isn't going to make my wife happy, but my plans for the 360 just changed.