hi

i have done several sets with hard seats installed for 1.74 valves for 383 s . use bronze guide liners also !

light port and blend and no problems . work good .045 milled off for compression .

intake side milled also .

Sounds like $100 too much. I throw 516 heads away when they come in my shop.

I would rather buy Edelbrock street heads, than the above china brands. I will get Eddys for the 440 build for a Satellite 68 I bought in december.

The 516 would be a budget build with homeporting the bowls. But I guess there is limit on how much to spend before new alum heads would be a much better choise.

Thanks for the info, any size or even better part nr for the hard seats? My machinist is a metric for mm instead of inches.
Milling the intake side is a good move.

S B I

is the brand he uses but i dont konw the part no .

Sent an e-mail to tech at S.B. international asking for the smallest outside diameter hard seat for a 1,74 valve.

Will have my machinist give me a total cost for both seat work and bronze guides, then will se if these heads will either end up in the attic, or on the 383-70 D200 truck of mine.

Here is the answer from SBI : I would recommend the SB1812-12 for the 1.74” valve.

Depth 7/32
Exact O.D. 1.8175
I.D. 1-5/8

That's all well and good if your customer has enough of a budget to spend $1200+ on new cylinder heads. Many do not.
Before you say you'll spend that much on rebuilding stock heads...that all depends on where you're located and who's doing the work. I've had stock cast iron heads rebuilt and spent way less than I see a lot on here quoting.
All depends on the end goal, but a pair of 516 heads can be made into very capable high performance heads that make good power.

Not without added costs over buying a core and just rebuilding them. Then you are stuck with iron heads that cost about as much as the Aluminum heads and don't make more HP, not to mention the AL heads still have room to improve if you want to go that route.

Stock rebuilt they are fine. You start porting and such then you have to think hard about how to spend your money.

If you have to spend more than $600 on a refresh, then you must go Aluminium.

But I would never spend time and effort on a 516 anyways!

I have wrecked several pairs trying to get the exhaust ports 'into shape'.

Some are cast with the very bad roof port bulge that cannot be enlarged.

But I recently came across some 516 castings 1964 and 1965 that have the later style '915' 'LARGE' exhaust port, go figure?

All the 1966 heads that I have ported and subsequently ruined have the collapsed roof...

So I cut my old 1966-516 race heads up to see why?

I'm guessing its a 'foundry flaw' with damaged casting-moulds from 'over use'...

Pictures to follow for anyone who 'maybe' interested lol...

Here´s my 516 from -66 that now have 2,14 and 1,74 Milodon valves.
New valve guides and hardened exhaust seats plus valves cost me as much as Edelbrock street heads.
Live and learn!

one thing i learned long ago, brand new heads can be junk out of the box. one of the most important parts on your engine! how well i know the sound of a great valve job when it first fires it off... you should spend whatever it takes to get them right no matter what head you use. if it cost to much , then you should save some more money!

Stuff is expensive to get done in Euroland these days!

I worked at a place called ''Rovercraft'' a specialist V8 workshop.
We very rarely did iron head work since the Millennium...

Seat work was always Aluminium heads and guides were 'knock out and re-fit new ones.
The last set of iron heads I had done was approx £250 to fit seats and 3-angle cut, per head!

Guides are always worn and some heads are on their second or third set of guides...



But now I see a different issue with heads!

Worn out 'stainless steel' exhaust-valve 'stems and seats', at an alarming rate...

The stainless is much softer than the older steel/alloy exhaust valves?

Now there is 'head warpage' too!

I took a set of Mopar performance '452 aluminuim' heads off a low mileage 440ci engine and one head was badly BENT/BOWED etc!

It was in fact 1/2mm which is 0.020 thousanths...

Once it had been machined flat the outer combustion chambers were way out of cc spec.
So you have to reseat the valves to match the centre cylinders and re-shape the chamber to get the volume right again.
Then you have to re-machine the rocker pedestal channels as they are 0.020 bowed as well...

All in all it was much work I would have called it scrap myself...

You fix one problem and get another...

If you own a pre 1966 car/truck and you are only grocery getting, then 516 heads are FINE!

My grocery getting days in a Mopar are well and truly over for me...

I love Mopar iron heads and am always happy to spend an hour or twenty on them.

My own bug-bear' with 516 heads is, they ''break through' real easy on the exhausts, even with mild port work...

They have a bad exhaust port and that's how it is...



The 'Stan Weiss' Flowchart is mind-blowing and takes some reading!

516 Intakes around 220 cfm which is poor.

No 915 'raised port' flow numbers, but they are basically 'closed chamber 906's.

A very trick 906 intake will get you somewhere near too 300 cfm's...COOLIO...

So if you can get 300cfm with any head you need approx, 75% for the exhaust too...(225 cfm).

There is one set of stock '2.08-1.74' 906 heads with 250cfm flow.
If you can start with those numbers you are onto a winner lol...