heads questions

[barnett468 418]

47 minutes ago, fnoble said:

 Thank you very much I really do appreciate this. I agree on the exhaust note - fun when I was a kid now that I’m 66 not quite as much fun,  like to keep the hearing I still have!  Would an Edelbrock 500 AVS squeeze a little more mileage out of it versus the 600 or would I be giving away top end ?

i am the right and the wrong person to ask about edelbrock carbs. i have been fine tuning carbs for over 40 years and you could not pay me enough money to put another one on a car. they work fine when they are properly tuned which is difficult to do and is sometimes impossible to do because of the limited jetting parts they supply in their $75.00 kit which you will most undoubtedly need unless you are the luckiest person on the planet and it actually works perfectly right out of the box.

in general, you will typically get the best mileage from a carb with annular boosters like the eddys and some holleys, some quick fuel and some summit racing carbs (old style shoe box holleys) have if it is not oversize for your app and if it is properly tuned. the second best mileage is typically from a carb with downleg stepped boosters but those are typically racing carbs and expensive.

if you are concerned about mileage you should leave your engine stock with maybe a high mileage type cam and run 3.43 gears with the aod instead of 3.50's.

 

[fnoble 0]

Truly, thank you for all of your help.

[fnoble 0]

Sorry still evolving, found a pair of 93 Cobra GT40 heads thinking mild port the intake you suggested from Summit. But, it says with GT40 heads to go up to step 2.h Should i stay at level 1 or move to level 2 based on everything I've already rambled about?

[barnett468 418]

4 minutes ago, fnoble said:

Sorry still evolving, found a pair of 93 Cobra GT40 heads thinking mild port the intake you suggested from Summit. But, it says with GT40 heads to go up to step 2.h Should i stay at level 1 or move to level 2 based on everything I've already rambled about?

Don't port an intake. What is step 2 and level 1 and level 2?

[fnoble 0]

Sorry, that should’ve read mild port on the heads, and do I go with the stage one - like a performer or step up to the RPM level with the GT 40 heads , because when I read the description and questions on the intake you suggested one of the questions was with GT 40 heads and it said because of the flowrate it would be better to step up to the stage two. Again am I right back to killing the flow velocity and low-end torque? Idle to 5500 is probably my goal,  I just keep getting sidetracked  from the mild bill that I want, to the go fast which would be fun!

 

[barnett468 418]

1 hour ago, fnoble said:

 I just keep getting sidetracked  from the mild bill that I want, to the go fast which would be fun!

 

With stock 289 heads and intake you can rev an engine to 6200 rpm if you have the right springs and cam etc. You are way overthinking your build.

 

[fnoble 0]

To be completely honest I'm doing a refi on my house I've got some stuff I needed to take care of so in the meantime I tacked on enough to do the Mustang so now all I have until that comes through is time to think. I'm at a point well there's not much left for me to take off of the Mustang I got to start buying stuff and putting it back together! Just wanted to use this time to talk to The Experts make sure I'm going to do it right so thank you again.

[1969_Mach1 333]

I don't know that I would include money in a mortgage to build a car.  Short on funds to do something for the car, no big deal it can wait a little.  Short on money for a mortgage payment, that's a bigger problem.  But that's just my way of thinking. 

[barnett468 418]

10 hours ago, fnoble said:

To be completely honest I'm doing a refi on my house I've got some stuff I needed to take care of so in the meantime I tacked on enough to do the Mustang so now all I have until that comes through is time to think. I'm at a point well there's not much left for me to take off of the Mustang I got to start buying stuff and putting it back together! Just wanted to use this time to talk to The Experts make sure I'm going to do it right so thank you again.

Why dont you start by taking your 351 heads to a shop and have them look at the valves and guides and valve seats to see what they need. Can you post photos of the combustion chambers? Do you think you are skilled enough to drill holes thru the head and rocker stud to install pins? Do the valve springs have rotators on them?

[fnoble 0]

Recent divorce.  I built the house 15 years ago it's financed at 6 1/2 % I can buy my portion of my fourplex from  the x,  can do that and money to build the car and still keep the mortgage $50 a month cheaper than what I'm paying now. At 67 , I will never pay off the house in the time I have left and toward the end it won't matter  so extending the payments is not a factor. My fourplex,  a 2 bedroom house and 2 three acre building lots are all paid for ( except for the yearly rent to the government ). Retired except for maintenance on the rentals, going to build myself a fun toy. Found some rebuilt GT40 heads I think I'll mildly port those and from what I'm reading I'll keep intake at performer level. rpm calculator  is telling me the 373   would keep me at 75 at about 2200 RPM,  (26 inch tires and the aod) High Enough so as not to keep shifting up and down on small inclines. We have some of those in the Black Hills.  It may not sound like it but with your help and some reading I'm narrowing this down!

[fnoble 0]

, the 351s would need Springs, exhaust seats ,valves,valves seals, valve job, and  one head  has a  broken  guide so the rebuilt GT40 heads are a better deal for me.

[1969_Mach1 333]

6 minutes ago, fnoble said:

Recent divorce.  I built the house 15 years ago it's financed at 6 1/2 % I can buy my portion of my fourplex from  the x,  can do that and money to build the car and still keep the mortgage $50 a month cheaper than what I'm paying now. At 67 , I will never pay off the house in the time I have left and toward the end it won't matter  so extending the payments is not a factor. My fourplex,  a 2 bedroom house and 2 three acre building lots are all paid for ( except for the yearly rent to the government ). Retired except for maintenance on the rentals, going to build myself a fun toy. Found some rebuilt GT40 heads I think I'll mildly port those and from what I'm reading I'll keep intake at performer level. rpm calculator  is telling me the 373   would keep me at 75 at about 2200 RPM,  (26 inch tires and the aod) High Enough so as not to keep shifting up and down on small inclines. We have some of those in the Black Hills.  It may not sound like it but with your help and some reading I'm narrowing this down!

That changes things a bit.  Hope it all works out okay for you.

 

1 hour ago, barnett468 said:

Why dont you start by taking your 351 heads to a shop and have them look at the valves and guides and valve seats to see what they need. Can you post photos of the combustion chambers? Do you think you are skilled enough to drill holes thru the head and rocker stud to install pins? Do the valve springs have rotators on them?

That's a good idea.  But with all that work, I wouldn't shortcut and pin the original rocker arm studs.  Especially on 351W heads.  I believe those are shouldered non adjustable rocker arm studs.  Automotive machine shops tend to charge a lot to machine for screw-in rocker arm studs.  Another route to save some money is remove the old studs yourself.  Then have the rocker arm stud bosses machined down (I think but not sure it's 0.230") at any machine shop.  It doesn't have to be an automotive machine shop to do that.  Then if you're skilled enough you can tap the holes 7/16-14 UNC for screw-in rocker arm studs yourself.  The original rocker arm stud holes are already the correct diameter for the tap.  Use a chamfer in a drill to dress up the top edge of the rocker stud holes.  And using a taper tap for starting threads makes it easier to tap straight by hand.

[barnett468 418]

3 hours ago, 1969_Mach1 said:

That's a good idea.  But with all that work, I wouldn't shortcut and pin the original rocker arm studs.  Especially on 351W heads.  I believe those are shouldered non adjustable rocker arm studs.  .

the non adjustable studs work fine for this app . i have used them many times for this exact app and so have countless others since around 1969 when the 351 heads became available and there are many threads online about it . all he needs is the correct length push rods which are easy to get . even if the push rods he gets are a little longer than what is ideal, he can simply install swedge nuts which are readily available at most hardware stores, and for extra insurance that the nuts won't loosen he can install a jam nut on the top. It is very simple process. Also, there is nothing wrong with pinning the studs in moderate builds because the spring pressures are not very high, besides, chevrolet used pins in the studs on the 67 thru 69 z28's of which i have had a few and I have never seen a  reported cases of the pins shearing and the stud lifting out of the head. 

I'm just offering a low budget option that will be 100% reliable in his case since he doesn't seem to have an abundance of money to throw at it and that $300.00 or so dollars he will be saving by pinning the studs instead of replacing them with screw in ones can be spent esewhere.

 

 

 

[barnett468 418]

Heck after reading your refi post, i would just consider just buying the eddy e street heads then and the 373 gears are still a little low for a mild engine unless you simy want to roast the bejesus out of your tires often from a dead stop 

[fnoble 0]

With the AOD and 26 inch tires 373’s at 75 miles an hour is 2531 for r.p.m. 355 gears is 2409.  At 65 miles an hour with 355 it’s 2087 373 is 2193  either of those seem well within the power band and they’re not more than 110 rpm difference . So with the 355s be lugging too much at 65 miles an hour. I do think I’ll buy the GT 40s rebuilt by Windy City engine for 550 they are the 93 cobra heads

[barnett468 418]

22 minutes ago, fnoble said:

So with the 355s be lugging too much at 65 miles an hour.

 

355's will not be lugging too much at 65 mph with the aod ratio i mentioned. I do this for a living every single day. 1950 rpm is around where your engine would be close to lugging. nothing "wrong" with 373 gears as long as you aren't spinning the engine at 2400 rpm or more for hours on end.

[fnoble 0]

Again thank you for your expertise 355 it is!

[barnett468 418]

40 minutes ago, fnoble said:

I do think I’ll buy the GT 40s rebuilt by Windy City engine for 550 they are the 93 cobra heads

ok, but if they are stock, you still need to replace all the valves and valve springs then have the seats checked to see where they hit the valves at then you still need to do some port work and still need to mill them so you probably need to add around $400.00 to their price not including any port work. also, you need to run short plugs with ceramic plug boots to prevent the boots from melting and arcing on the exhaust and it will be a bit of a challenge to tighten the plugs because your plug wrench will probably hit the exhaust unless you use gt40 headers but i don't know if those will clear your shock towers.

.

 

 

[barnett468 418]

8 minutes ago, fnoble said:

Again thank you for your expertise 355 it is!

believe me, it will still be quite "sporty" off the line with those and a 2000 rpm stall converter when you floor it but it will be far more pleasant and a little more economical to cruise long distances with.

 

 

[fnoble 0]

So....e heads and 2.43 gears didn't you tell me that already? Sometimes I'm not really good at thinking and listening at the same time!    

[fnoble 0]

 

Oops 3.43 Again thank you for your expertise you are a great asset for this site!

[barnett468 418]

5 minutes ago, fnoble said:

So....e heads and 2.43 gears didn't you tell me that already?

Sometimes I'm not really good at thinking and listening at the same time!    

No, I never said 2.43 gears and they don't even make those. In my opinion, 3.55 or 3.43 gears.

Yes, I think e street heads are one of just a couple extremely good options for you if you decide to get new heads. The e street heads are made from the exact same casting that their rpm heads are and use the same mfg for valve seats and valves. It's mainly that the valve springs aren't good for high perf apps but you are not building a 350 hp 302 and don't plan to rev it more than around 5500 rpm, so the springs that come with them are fine. if you want one of the best heads i would look at afr's and twisted wedge but those are way overkill and way overpriced for your app.

[barnett468 418]

36 minutes ago, fnoble said:

 

If you don't mind paying for premium gas, you could mill the e street heads to 56 cc's with the pistons i mentioned if your block will clean up at .020" over, then zero deck the block and use the cometic .035" thick gasket but have them make the gasket bore the same size as the cylinder bore and this will get you around 10.0 compression. if you want to give up just a little power and use 89 octane, you can mill the heads to maybe 58 cc's

 

 

[fnoble 0]

What do you think of the 2027 kit from Edelbrock? reading through the contents pretty much everything I was thinking about getting anyway they upgraded the valve springs from 1.25 to 1.46 diameter with damper spring and also improved the keepers and studs. I'm still finding some old kits out there with the 125 valve diameter but the one at Summit looks like the best kit it includes head bolts cam, lifters,  pushrods gaskets e heads 2121 intake timing chain. If nothing else the E heads are better now different suppliers for the Springs keepers and studs for them.

[fnoble 0]

A little more cam would be nice!