Hello, I'm a newbie on this forum but have a few questions. I'm looking at building a FE 390 for a '76 F250 4x4. Maybe something in the 300-350hp range but really would like gobs of torque. Mostly likely It won't see much over 5000rpm's. I've read through some post about the Performer manifold and the Crane 941 cams. These both look promising. What's every ones thoughts about them? I'm kinda up in the air about a carb. 20 years ago I did a stock 360 with a slightly bigger cam {I think it was the Crane 266 or 268} I topped it off with a Quadrajet carb. It ran very well for a fairly stock engine. Are there any thoughts about them? I know they are 750cfm, and that is way more than I need but it ran so well I'm considering it again. Or would an Edelbrock 1406 with 600cfm be better for bottom end torque? I just planning a 390 bored .030 over but am open to all suggestions. Port work, headers {what size}, manifold, carb. Give me all your suggestion.

Please give me some hp ranges if possible.

Thank you

 

I'll go first, but by no means should you listen to only me.

Here goes:

D2TE-AA or C8AE-H heads, exhaust porting, maybe remove any snot in the intake valve bowl. Don't go nuts in the intake ports and by no means do you want to polish the intake ports. Hardened exhaust seats. You might want to oversize the exhaust valves, using 428CJ-size exhaust valves (1.650").

Use 360 pistons, that bumps the compression up to a decent level without going TOO far. Someone else should chime in on this, I've never done it, but some here have.

Intake: Edelbrock performer RPM, or if you happen to find one very cheap, a regular Edelbrock Performer or stock cast-iron 4bbl (basically the same thing). There may be other alternatives, but the easiest to come by is the stocker or Edelbrock.

Carb: Holley 600 or equivalent. Depends on how much tuning you want to do, and how easily you want to do it. If you want torque, stay small on the 4bbl carb.

If you're really ambitious and want a torque-monster, find a 428 crank, get 410 pistons, and make a 410. But you're starting to go up in $'s at that point because you also need the right flywheel.

Whatever you do, figure out what compression you're going to come up with and find a matching cam. Use whatever valve springs the cam manufacturer recommends.

And last, pass it all by the guys here, to make sure your cam and compression are a decent match. There's nothing worse than getting that wrong. And, degree the cam for what you intend.

On EDIT: When you used that Quadrajet, it is a spread-bore carb, so the primaries are smaller than the secondaries. The smaller the primaries, the better the low-end throttle response and torque will be. So the QJ is a good carb for that, but ... better off with a square-bore carb.

 

Can you explain why the 360 pistons? I was kinda under the impression that the 390 would be better. What is the difference in the RPM intake and the standard Performer intake? Were those heads that you mentioned found on many different FE engines or were they particular to a certain CID?

I found a cheap 360 locally. can I do all this to the 360? I've found 390 rods also, just need the crank now. Will the 428 crank work in the 360 block?

Thank you for the first response. I thought maybe I would have a few more by now, but thats ok. Any suggestion will help.

Thanks, dslman1

 

In order of asking:

The 360 pistons have a lower pin height, which pushes the piston further up the bore. The low-compression 390 pistons are WAY too low, and high-compression (flat tops) are way too high (11:1 or so) unless you go to a BIG cam. I think the 360 pistons also have a nice "quench" but you'd have to ask others about that.

The intakes: The Edelbrock performer is basically a stock cast-iron 4bbl intake. The Performer RPM has bigger ports, allowing better high-end, and doesn't seem to effect low-end torque at all. So in order of preference: Performer RPM, Performer, stock 4bbl.

The heads: Found on any truck 360/390 from 1972 on will be the D2TE-AA heads. The C8AE-H heads are any earlier 360/390 truck motor and many passenger cars from 1968 on. If you found a 360 from ANY year from 1968 and up, it would have either C8AE-H or D2TE-AA heads.

You can use 390 rods with a 428 crank, and get a 410, and put it all into a 360 block. 360, 390 and 410 blocks are all the same bore. The 428 crank will work with a 360/390 block, but you need a 428 flywheel, and maybe the harmonic balancer (not sure on that), and you're better off getting the whole thing balanced no matter what you do.

 

Are all 390 cranks the same? I just found a 390 crank from a 66-67 Fairlane with a casting of 2U on it. It's a virgin crank, never been turned down.

Thanks,
dslman1

 

2U is indeed a stock 390 crank. "360 pistons" are generally just 390 car pistons installed down in the hole due to the shorter stroke, while 390 pickup pistons are just 410 Mercury pistons down in the hole. You'll need a set of 390, 410, or 428 rods in place of the 360's as they are different. Late-'60's car 390-2V dished pistons will give you a little oooph at 9.5:1 without going overboard and will work with a "torque" cam. As you've stated what you want, low-end torque (some folks will try to sell you on a build for a hot-rod car, while you are clearly looking to build a proper pickup engine), your choice of the Performer is correct, and is a good improvement in torque & mileage over the stock iron manifold- it is NOT a high-RPM screamer manifold, it's a low-end push you back in the seat from idle manifold. The RPM manifold has to give up some of that low-end to be strong up top. If you were doing a bigger engine then the RPM would come into it's own. Holley #1850 600CFM carb, decent headers & exhaust

 

If you ran a Q-jet and liked it before, you will like it again. I'm running a 800 cfm qjet on my 390 and love it way more than the small Edelbrock 1406 600 cfm Carter style carb design that was obsolete in '67... The rochester quadrajet is a varible cfm carb and will only flow what the engine requires. Gm used them on engines from the 305 all the way up... Ford even used them in '70 and '71 on the 429... The qjet's small primaries are more than enough for daily street driving with great economy + the added bonus of the huge secondaries for those times you want to have some fun.. To set it up right, check out - Cliffs High Performance Quadrajets :: Qjet Carburetor Rebuild Kits, Parts, Bushing Kits, Carb Tuning - buy the book, and read it twice.....
I did use a Edelbrock #1483 ford kick down linkage adapter to make the carb work on my automatic application or you may use a lokar kickdown cable kit. I also used a 4 hole adapter plate Trans-Dapt 2034 flipped over and modified slightly to fit, I'm running a Crane Cam 343901 for the street... Remember, gear ratios and tire sizes also affect cam cruise rpms.... and with a dual plane perfomer intake and good headers I'm good to go..... Whatever you end up running, get a vacuum gauge and dial it in for highest vacuum for the best performance and economy... Then, just enjoy the ride....

 

I am getting a lot of great info from this thread. I also have a 360 that I want to rebuild with a 390 crank etc. I'm not looking for gobs of torque but for a decent street engine that could pull a load if it had to. How would using the 360 pistons with the 390 rods and crank work? I'm new to engine building. Does the .284" difference in the stroke not cause an interference anywhere as the piston enters the chamber? Or does the 360 piston just peek over the top of the block to add more compression? What would the compression be with the 360 truck pistons? I have a '70 360 out of my F-100 with C8AE-H heads that I had rebuilt to stock.