516 heads on a 400

[machelis]

Howdy,

I have a 1972 400 with 213 heads. I want the heads for another project, but I still want to drive my satellite with the 400 in it in the meantime. I have a set of 516 heads that need a rebuild.

Will the 516 heads go on without any problems? It's going from open to closed chamber with an already low cr. Will I actually gain any power? Or would that only come with bigger exhaust valve and some porting? Im not looking to gain power necessarily, but I'd rather gain than lose. It's not for racing and I know they aren't hardened seats.

Engine has a Holley dominator intake, 750 cfm carb and 1 3/4 hedmen headers if that makes a difference.

Thanks

 

[Don Frelier]

Should go right on. I would not worry about the seats. It's old cast iron that's been heat cycled. You will gain some compression.

 

[69Bee]

If you were my customer, I would be recommending: clean $45, install valve guides $76, install larger valves, open throats for larger valves $80, install hard exhaust seats $96, valve job $100, surface heads $60, assemble. Parts required, new guides $32, exhaust seats $30, valves (depends on OEM or stainless, springs (depends on OEM, RV, or name brand). Labor would be $457, parts about $200 or so, epa/shop supplies $15 +tax. If you are going to spend money on the heads, do it once as it will be cheaper... They will physically fit, and will raise compression due to the closed chamber.

 

[machelis]

Thanks for the recommendation. If you lived closer to me, I would be your customer!

I'm really just looking for a cleaning, resurface, new valves and springs. But I have a price idea now if I decide to go the whole 9 yards.

 

[Donakey]

Why not pay for the shipping.I have some ZEEKER heads I’m going to build.Im in Canada.Lets talk.I would like to send them to you 69 Bee. You have any ideas what the most economical way to send them is?

 

[66Satellite47]

I've ported several sets of 516's with very good success. On any BB Mopar head, pocket porting gets you a ton of performance. You still need the good valve guides, quality valve job. The larger valves sure would help, a 2.14/1.81 isn't hard to do. They may not be the best, but still will work darn well.
Hey , the Zeeker heads would be a treat, wish I had bought them back in the day.

 

[BeeKool]

If your looking at spending $700 on rebuilding the 516s. Consider spending a few hundred more amd going with aluminum eddys.
Or order some already rebuilt from Indy. They are 5-600 IIRC

 

[partsmonsta]

make sure your engine guy check Valve Clearance. The 516s are closed chamber heads. Been using them to race for years. Gimee stock heads over aluminum ANY DAY.

 

[69a100]

When I redid my 516's, I had the exhausts drilled out to 1.74's and did a pocket port on them. Breaths a lot easier now. Good Luck

 

[machelis]

69bee and donakey,

I'm just west of Montreal, Quebec so I could always shoot down across the border and ship them. I'll find out some prices and go from there.

 

[wyrmrider]

Take out 1.74 exhaust valves should be free from any shop doing the 1.81 upgrades
I just pitched a bunch of them
they can be in good shape while the intakes are junk.
new HP springs are reasonable
use premium seals
guides are the key to a VJ lasting
you do notice you can get close to the price of new heads unless you shop wisely and have a friendly machine shop and do a DIY pocket port job

 

[machelis]

Now this has me begging the question of having these heads done properly and once, like 69bee said, and just tossing in a purple Cam, new timing chain and holding off on the other build for now.

The snowball effect has started.

 

[wyrmrider]

Purple cams are way obsolete
get your compression exact first
and then all the weight, gears, converter etc info before thinking which cam
They made non HP 400s with both the big and HP size converters- figure out which one you have- they went to the looser converter to compensate for the loss of low end with the compression drops
The stock cams also leave a lot to be desired as far as overlap and late intake close which kills dynamic compression and late ex close which dilutes the intake charge (like EGR)is concerned so there is lots of room for improvement
headers do make a difference
you will pick up some compression but you most likely do not have as much now as you think you do- find out
how do you want it to drive?
towing
daily driver
weekend warrior hot rod
street strip
think hard and be realistic

 

[bm02tj]

I have a 73 SSB I bought in 74 with a bug catcher air cleaner that ate the motor
and had to bore to .040 then stuck on the 516 heads from a 66 383 and opened to the 400 valves
no seats as back then we had lead
Start with a stock 6 pak cam the changed to a 440 mag cam
always ran great on regular gas

 

[wyrmrider]

6 pack and magnum cams are the same as far as timing/ profile are concerned
you can't get 6 pack (larger radius) lifters anymore
you would have to reface stock (Magnum) lifters- not that this is bad
You still did not have much compression but more than 400 heads
Should run fine even on Mexican regular
more modern cam could have much more dynamic compression and more lift/area
the stock cams are that lazy

 

[machelis]

Would the cam from a 76-77 truck 440 make a difference? I have one on hand.

 

[wyrmrider]

Compared to a Magnum cam yes
problem with the Magnum cam is the way long and late exhaust close then the long and late intake close

Standard 440 cam is much shorter on the ex close (ex dilution, reversion)
That said both are terrible, they run hot and they do not make good torque
The HP cam makes hp on good gas at higher rpm, otherwise they both just make heat (in low compression engines) the stock cam was designed 50 years ago for a advertised 10:1 and needs a real 9:1 to work 9.5 is better

problem is anything with no quench is tough- you will need to work on your advance and vac advance curves

if you have the lifters install it advanced 4 degrees
but only if you have no other options
If you have to buy lifters then I would suggest a more modern profile

what do you figure your CR is now exactly still low 8's?

 

[machelis]

I was hoping, realistically, low 8s with the 516 heads. It's stock with intake, carb and headers. If I can get more pep in my step with what I have plus proper tuning, then it's worth it for me. If it requires a higher cr, then I may as well spend only what's necessary and put the rest in to the other engine.

I was told the 400 was from 72 newport. But it came with a 4 barrel intake. I'll check the stamp to see if it really is, or if it's the hp. At least I'll know what cam is in there.

 

[machelis]

More details I forgot to add.

2.94 gears, weekend cruiser with the odd trip to the strip for fun.

I just read up on Hughes whiplash cams. Would it be on the same page as a purple Cam? Or an actual decent option?

 

[wyrmrider]

depends on which whiplash and which purple
you can "whiplash" any cam
all they are is a bigger than usual intake lobe for that size cam and squeeze the lobe centers together to get the intake closed somewhat earlier at the expense of more overlap
(the no free lunch)
I posted this in another thread
comparing the best low compression special with the 260 purple shaft
The 260 purple shaft has the same intake duration as the stock non magnum cam but has more area
special shaft
265 @.004 284
256° @.006 269
246 @.008 260
202° @.050 212 newer grind may be 221/228 some were 221/221 over the years
120 @ 200 115
64 @ 275 DC 260 is 42

If we split the difference in the 20 degree seat timing difference you can see that we could close the intake 10 degrees sooner- which is much better than the 4 degree advance suggestions

That builds dynamic compression big time
the 64 degrees above .275 is right at the intake lobe center of say 110 which is where the most velocity is needed

Neither of the Mopar grinds have any duration at .275 because they do not have that much total lift- so you get more cylinder fill = power than stock cams
The stock cams only have about .250 lift max where the special cam has .305
Lots of progress in the last 50 years even-though the Special Cam was done maybe 30 years ago for the then popular 440 low compression motorhomes
you can do the math yourself on how much overlap is reduced
so if you do not want to do pistons this is best answer
and may still be best answer with 9:1 iron heads with your weight and gears
cheers