I'd like valve spring recommendations for my 390 build

[dmann]

Hello,  I'm completely new to FE engines.  I have a 1971 F250 with a 390 engine, which was rebuilt prior to me purchasing the truck.  I decided to do some upgrades before I take the truck on some family vacations towing a 24 foot camper.  I did find that the truck has a 3.5 something rear gear (can't remember how I found it, I think I read a tag with the info) and a C6 transmission.  I want to save this truck and pass it down to my son, so I decided that I could spend some money on it to jazz it up a little.  I purchased the new Edelbrock Pro-Flo 4 EFI system, headers, Hughes XTM towing torque converter, and some misc upgrades like a classic auto air AC system.  I decided to pull the front end off and yank the motor so that I could clean up the frame a bit and handle some rust on the inner fenders and install the torque converter.

The previous owner told me that an "RV cam" was installed but there are no specs at all.  Since I'm going to have the engine out I thought I'd upgrade the cam...and a friend of mine at work is retrofitting an LS into his old Chevy truck.  He was getting a new roller cam and so I thought I would also.  I purchased a cam and lifter kit from the Lunati website.  The cam is a small roller cam and the specs are:

Advertised Duration (Int/Exh): 262/270
Duration @ .050 (Int/Exh): 211/219
Gross Valve Lift (Int/Exh): .559/.559
LSA/ICL: 112/106
Valve Lash (Int/Exh): Hyd/Hyd
RPM Range: 1600-5600
Includes: Cam & Lifters (#72336-16)
Part Number: 20330710LK

I've done cam swaps before this in other engines (Chevy) but they were small flat tappet cams.  After the purchase I realized that I didn't know JACK about FE engines and that I had no business buying a cam when I don't know anything about FE valve train.  I just purchased two books: Ford FE Engines: How to Rebuild and How to Build Max-Performance Ford FE Engines (Performance How-To).  I'm going to read those books and see if I can figure out what parts I need to buy or what machine work is needed to run this cam.

I'd like to get in contact with some folks who know FEs and get opinions on where I should go next.  I tried to call Survival but I didn't have any luck getting through (I'm in PST timezone though, so maybe I need to call earlier).

Could anyone offer a kind word of advice to someone who needs training wheels with FE engines?

At least I didn't commit the biggest sin and stick and LS in it :-)

Best Regards,

Dan

[blykins]

Do you know your install height?

[manofmerc]

I would contact lunati its their camshaft they will know what springs to use .Get new retainers and keepers also .When specing the retainers don't forget your valves are 3/8" .And like Brent said knowing the valvespring installed height would be useful .

[My427stang]

Stick with Brent, he does a ton of these and Manomerc has the right idea too, but I put less stock in the companies, although Lunati is good, you need to get them on the right track

Some comments:

1 - You will need both retainers and springs as you likely have the heavy two piece retainers now.  Those retainers also don't leave much room for a seal and you are significantly adding lift at .560 or so

2 - Time to replace your valve seals with a good positively located Viton (not white Teflon).  The EFI will be using an O2 sensor and you want to keep the exhaust as clean as you can. 

3 - Since you have the engine out and intake off, I would consider pulling the heads and having the guides checked at least. 

4 - Good cam choice for the use.  BTW, you are likely at 1.81 installed height stock, but best to measure

5 - Easy to start spending your money here, but you are also pretty good at it yourself   When you get in there, you may find this is a low compression truck 390, you can tell by the pistons being way below deck at TDC.  If it is, you may want to consider going whole hog and rebuilding it.  It isn't a must-do, but with likely 3 grand of parts now, may as well do it right.  Either a nice zero deck 390, 410, or even a 445.  Sounds crazy, but if you are at 8:1 compression and .100 deck clearance, you'll be happy after you bite the bullet compared to where you would be

[dmann]

I just pulled my heads but I haven't disassembled them yet, and I also just checked the pistons and they are around .130 to .140 thousandths below the deck at TDC.  They are some sort of replacement piston from the looks of them, they have a mark that appears to show they are .020 oversized.

[My427stang]

So likely a truck 390 or maybe a 360, better measure stroke.

If it has the truck 390 pistons, you can swap a 428 crank in it and make a 410 (assuming the parts are good and likely have someone cut the ridge)

If it's a 360, you can get a 390 crank and rods and it will be a nice little zero deck 390 at about 9.25:1

[FElony]

So likely a truck 390 or maybe a 360, better measure stroke.

If it has the truck 390 pistons, you can swap a 428 crank in it and make a 410 (assuming the parts are good and likely have someone cut the ridge)

If it's a 360, you can get a 390 crank and rods and it will be a nice little zero deck 390 at about 9.25:1

Or you can put a turbo on it.

[dmann]

Well I ordered some of those Trick Flow heads, I guess we'll see where that gets me.  I won't be doing the stroker this year but perhaps next year.  At this point I just hope for something a little bit better than what I had.  I guess I'll need to get it assembled figure out what pushrods I'll need.  I ordered that compcams roller rocker setup also so I should have some degree of adjustability.  I really want to get this thing back on the road quickly...I miss driving it.  I'll post back with updates about what worked and what failed.

[My427stang]

Depending which pistons you have and which head gasket you pick, you could be under 8:1 compression. 

On the good side it'll run on any fuel you put in there

[dmann]

That's probably good, because I'll be towing a 24 foot camper with this thing...and it's likely I'll tow in the mountains from time to time.  I ended up with these head gaskets: FEL-1020.  I don't think they'll help my compression ratio, will they?

[blykins]

Give us a yell before you drop anymore coin on parts.

The Comp Cams setup is extreme overkill. 

The TFS heads look promising, but there is a huge rocker arm geometry problem.  You can't just slap these heads and rockers on and be good.   The rocker stand pads are raised by a net amount of about .250".  If you just bolt everything together, it won't be easy on the valve guides and seals.

[dmann]

Thanks Blykins - I'll get it mocked up and see what it looks like.  I'll take measurements and pictures.  Unfortunately for me I only have a lathe but not a mill :-( so if I need something milled I'll have to outsource it.  I really would like to get a mill at some point though.  It sounds like my cam won't be ready until next week.

[blykins]

The cam may take a bit.  Most suppliers are all out of FE cam cores right now. 

[FElony]

Give us a yell before you drop anymore coin on parts.

The Comp Cams setup is extreme overkill. 

He said it was a Lunati, and Ross said it was a good choice.

[FElony]

Depending which pistons you have and which head gasket you pick, you could be under 8:1 compression. 

On the good side it'll run on any fuel you put in there

Or he can put a turbo on it and not worry about too-big ports on too-small engine. 

[blykins]

Give us a yell before you drop anymore coin on parts.

The Comp Cams setup is extreme overkill. 

He said it was a Lunati, and Ross said it was a good choice.

He said he ordered Comp Cams *rocker arms* and *I* said that they were overkill....

[dmann]

I do have a new EFR6758 turbo in my garage right now which would be too small, but if I added a second one...

But probably not very reliable with a stock lower end.  The turbo is currently reserved for an old Volvo I have anyway.

Depending which pistons you have and which head gasket you pick, you could be under 8:1 compression. 

On the good side it'll run on any fuel you put in there

Or he can put a turbo on it and not worry about too-big ports on too-small engine. 

[My427stang]

So 8:1 will make it pretty mellow compared to something higher, but I will tell you, I resurrected a build gone bad for a local guy.

Same 390, same 8:1 compression, fresh build.  It's on the forum somewhere when I did it.  Edel heads, RPM intake, 800 Edel carb, and FPA headers and a 279 adv Thumpr cam in a little 67 F100

It was not fast, LOL, but it ran surprisingly well even with lreal ow compression and it was far overcammed and too much intake.  Even had a close ratio toploader in it until we swapped it for aan early TKO, similar to the TKO-500

I'd love to see you stroke that thing and make some compression and torque, but sometimes even a little one will surprise you.

I personally would return those rockers, listen to Brent, buy a set of aftermarket stands, cut them down and run stock hyd rockers.  It'll be bullet proof.  I am baffled on what it'll make for power, but the heads should let it hang in there, might want to consider an RPM intake to take advantage of them

[FElony]

Give us a yell before you drop anymore coin on parts.

The Comp Cams setup is extreme overkill. 

He said it was a Lunati, and Ross said it was a good choice.

He said he ordered Comp Cams *rocker arms* and *I* said that they were overkill....

Hey, don't you come back at me with actual facts like that when I'm on a posting roll!

[FElony]

I do have a new EFR6758 turbo in my garage right now which would be too small, but if I added a second one...

But probably not very reliable with a stock lower end.  The turbo is currently reserved for an old Volvo I have anyway.

I think the stock lower end is tougher than you might think.

[FElony]

... might want to consider an RPM intake to take advantage of them

Did I see someone match up TFS heads to a BBM Tunnel Wedge, or was I high at the time? Sorry to derail. It'll never ever happen again. Honest. I promise.

[dmann]

So an eagle 428 crank is only a little over $400?  Would I need the external balance flex plate with this crank https://www.summitracing.com/parts/esp-104283980?

Here's a link to the external balance flex plate: https://www.summitracing.com/parts/atp-z242.   Worth doing?

[blykins]

If you're willing to buy a crank and pistons, I'd wait and go whole hog on a long stroke crankshaft. 

I also wouldn't advise the use of an Eagle crankshaft in an FE. 

[dmann]

I was thinking of buying only the crank, flex plate, and bearings. I’d gain about 20 cubes and some compression (I calculated about 1.5 or so points).  My existing pistons look new...previous owner of the vehicle said it was very recently rebuilt.  I'll need to pull a piston out and check the bore for taper.

Scat crank instead of Eagle?

[blykins]

Are you for sure it's a 390? 

Another concern I would have would be piston/valve clearance with the larger 2.190" intake valves on those TFS heads.

[dmann]

Ok, I’ll do the stroker 445.  I’ll take it in to my local shop and get it prepped.  Recommendation on pistons and compression ratios?  This is my “fun” vehicle that sees towing duty.

[blykins]

I'd aim for around the 9.7-9.8:1 mark.  I have some towing application engines out there that do well with that compression ratio.  You'll need a piston with around 25-26cc dish to do that.  I have two pair of TFS heads in here right now and they both come in at a hair under 70cc.

Your cam will be a little on the small side for 50 more cubes but it should be ok if you have to keep it. 

[dmann]

Thanks Brent, I'll take that info to my machinist.  I ordered an FEpower timing cover in the thought that someday I might want a different cam without having to pull the cover.

Dan