400BB Heads Question

[badvs3vil]

First off, I want to thank a lot of you for answering all of my noob questions without making feel dumb, I do that enough myself... LOL

My question is simple enough I guess. My heads do need a valve job at the least. At what point should I look at getting new heads? These are 452 Iron Heads for a 400 Big Block btw.

What does a normal head rebuild cost?

Questions like that.

Thoughts?

 

[Davea Lux]

A valve job with new valves and bronze guides installed will run in the neighborhood of $600-$800 depending on where you have it done and if new hard seats are needed. The 452 heads have induction hardened valve seats, sometimes these wear thru from use or valve grinding. If that is the case, you will be looking at about the $800 figure. The 400 is a low compression smog engine, so it is not going to be cost effective to add after market aluminum heads unless the engine is being rebuilt with higher compression pistons. If the car is a daily driver and not destined for a performance update, rebuild you existing heads and call it good.

Dave

 

[badvs3vil]

A valve job with new valves and bronze guides installed will run in the neighborhood of $600-$800 depending on where you have it done and if new hard seats are needed. The 452 heads have induction hardened valve seats, sometimes these wear thru from use or valve grinding. If that is the case, you will be looking at about the $800 figure. The 400 is a low compression smog engine, so it is not going to be cost effective to add after market aluminum heads unless the engine is being rebuilt with higher compression pistons. If the car is a daily driver and not destined for a performance update, rebuild you existing heads and call it good.

Dave

Thanks Dave. Yeah this will be a daily driver that can do a burnout, Im hoping.

So I guess what I need to figure out then, is what cam to match up to the 452 heads. Seems .460 was a good number when I asked before.

 

[MEV]

The 440 source heads are an almost exact copy of the 906 heads right out of the box, you will have a hard time beating them on you 400 for the money, low compression or not. They are currently out of stock I just noticed. I would give them a call, they are easy to work with.

 

[badvs3vil]

The 440 source heads are an almost exact copy of the 906 heads right out of the box, you will have a hard time beating them on you 400 for the money, low compression or not. They are currently out of stock I just noticed. I would give them a call, they are easy to work with.

How much did those run?

 

[badvs3vil]

The 440 source heads are an almost exact copy of the 906 heads right out of the box, you will have a hard time beating them on you 400 for the money, low compression or not. They are currently out of stock I just noticed. I would give them a call, they are easy to work with.

I called them, they are back ordered 4-5 months and they have no ordering process for them until they are in stock.

 

[Luke Pokrajac]

I've had GREAT luck with 440 source heads on my 68 sport fury H code 383. My 906's were worn out at 125K miles and many of the exhaust valves were recessed into the heads, especially the center side by side exhaust valves. Your 452's look better than my heads did. My engine is a true 0 deck from the factory 383....at least it is on one cylinder. I measured at TDC and wasnt able to get a feeler gauge in under a straight edge. The 440 source heads are closed chamber which work excellent with a zero deck piston. I currently have right around .039 quench with the felpro gasket. I cant tell you how much better the engine runs with the 440 source heads...and it runs cooler. I picked up the 440 source heads at right around 1000. I had a machinist go through them and the valves did need cut. I checked the heads in a pitch black garage with a LED flashlight...I saw dim light coming through around some of the valves, mainly intake valves. I've heard that all aftermarket heads should be gone through and most need valves cut. My engine REALLY compression brakes now when you let off the gas. I'm running around 160-165 PSI compression pressure.

 

[Luke Pokrajac]

 

[badvs3vil]

Well, if I cant find any 440 sources until middle of next year, what about something like this?

ProMaxx Performance 9440: 440 MAXX Aluminum Cylinder Heads Big Block Chrysler (B/RB) - JEGS High Performance

 

[Luke Pokrajac]

The Promax have same specs as 440 source...same chamber size, same valve size and inlet port size. Big difference I see is the casting doesnt look like your 452's. The stealth heads are made to look just like the Chrysler heads...if you paint them folks generally wont know you have aftermarket heads on.

 

[CBODY67]

My late machine shop operative would touch the seats on even a new head casting. Or on complete heads (new) which customers would bring in. No matter what.

FWIW,
CBODY67

 

[Luke Pokrajac]

Given the great luck I had with 440 source heads...I had a terrible time with comp pushrods. When I put the aluminum heads on I had just a bit too little preload on the lifter with the aftermarket comp pushrods I put in when I did a cam swap in 2020. The valves were a bit noisy when the engine warmed up...almost like a solid lifter cam. The thing to keep in mind with aluminum heads...they transmit noise much more readily than cast iron heads. I have a lunati 256 cam in the engine and it has fast ramps which most modern cams have. Never noticed noise with cast iron heads but I could hear it with the aluminum heads. I took all the comp pushrods out and they were all over the place in length...off by .010 or more from rod to rod. Only one or two were at 8.575 spec. Some were 8.560. Not knowing the full definition of lifter preload, I ordered longer pushrods around 8.600. That was a bad move. I put #7 piston into the intake valve and bent it. Had to pull the head back off and replace a valve. I ended up ordering 3 sets of 8.575 Comp pushrods from Amazon and measured 48 of them to get close to the stated spec. Kept one set of 16 and sent the others back to amazon. I have right around .030-.040 preload on all lifters. Chryslers can be a bear with their non-adjustment rocker system.

 

[1970FuryConv]

Well, if I cant find any 440 sources until middle of next year, what about something like this?

ProMaxx Performance 9440: 440 MAXX Aluminum Cylinder Heads Big Block Chrysler (B/RB) - JEGS High Performance

These are 84cc chamber so you won't gain much compression.
They have a 6-bolt valve cover, so stock valve covers might work.
They have standard port locations, so your exhaust manifold and intake manifolds might bolt on too.
I have never used these, but they look OK. If your 452 heads are worn out at the valve seats, these would be a nice upgrade.

 

[70bigblockdodge]

First off.
Why are your heads off?
Was it doing anything wrong?
Did you do a compression check before you removed the head?
Is this just a rebuild because it's winter?
If everything was fine before, chances are you will not be $1000 into a valve job with the most durable head they made for a BB Chrysler.
There are some improvements to be made, they cost money, and will not be done by average local machine shop.
Your compression is dead low, like 7.2:1, even a 75cc stealth head your mechanical ratio will only come up to 8.2 or so. With a aluminum head this will terrible, so there is 5-6 months and $1200 your not getting back. Have your heads done by a less than full anal retentive machinist (good luck finding one). New one piece valves are nice and add flow(at low cam lift) and reliability, but at 7.2 cr is that a issue?
If they were in good shape when taken off they should be able to be freshened for not too much $. Have a shop look at them. If they tell you they need everything without taking them apart, find another shop.
Edit: the seats on 452 castings are true induction harden seats, very deep into the iron not like the surface harding in previous heads. Beware the shop that tells you they will need changed.
I have a set on my Charger (68k miles on them) all I did was, measure the guides/stems, grind the lip off the stock valves and lap them in. The car never uses a quart of oil in the whole season of fair weather driving. ~10k in 4 years, I change it every spring.

 

[MericaMopar]

For a cam, I will be going with a hughe's whiplash cam. Something to look into for yourself. I have 452 heads and stock engine, the whiplash is supposed to raise dynamic compression and has a unique cam profile to produce power with a low compression/smogger era engine. I just need to get around rebuilding the engine I got to replace my cracked block 361.

 

[badvs3vil]

Well, I called around a couple more machine shops. I found one that has a 1 week turn around on heads and runs around $400 per head to have them refreshed. So for $800 I can have these 452 refinsihed. I think I might just go that route. It will save a few hundred bucks and if I am not going to gain much by going to aftermarket heads, why not just refresh these right?

I have a few people tell me about that Whiplash cam. I think I will look in that next. The machine shop did say he will measure the springs in these 452's to make sure what the lift is, in case they got replaced at some point. I can use that info for the new cam I will get.

 

[MEV]

Dont forget, you can run higher compression and still get by with regular un-leaded gas with an aluminum head, although in your case you will not be anywhere near detonation. Since you didnt ask for my opinion, here it is. Buy the aftetmarket aluminum heads if you can find them instock (edelbrock heads are made in usa) so they wont be affected by the supply chain issues, although they may have issues with the vacuum advance canister on your distributor, (easily remedied) i would have the heads machined to decrease the combustion chamber size, while adding an appropriate sized camshaft (hydraulic roller cams are sweet but can be spendy)and carefully checking for piston to valve clearance issues, again i cant imagine any problems even with taking a large cut off of the heads. If you wanted some more, add a aluminum dual plane intake and an appropriately sized carb. I am partial to quickfuel and AED carbs. I think with the shaved heads and mild cam you should be looking at 350-400 horsepower. Perhaps a bit more if you change out the stock manifold and carb, and add some good long tube headders. The stock bottom end will be fine.

 

[70bigblockdodge]

Dont forget, you can run higher compression and still get by with regular un-leaded gas with an aluminum head, although in your case you will not be anywhere near detonation. Since you didnt ask for my opinion, here it is. Buy the aftetmarket aluminum heads if you can find them instock (edelbrock heads are made in usa) so they wont be affected by the supply chain issues, although they may have issues with the vacuum advance canister on your distributor, (easily remedied) i would have the heads machined to decrease the combustion chamber size, while adding an appropriate sized camshaft (hydraulic roller cams are sweet but can be spendy)and carefully checking for piston to valve clearance issues, again i cant imagine any problems even with taking a large cut off of the heads. If you wanted some more, add a aluminum dual plane intake and an appropriately sized carb. I am partial to quickfuel and AED carbs. I think with the shaved heads and mild cam you should be looking at 350-400 horsepower. Perhaps a bit more if you change out the stock manifold and carb, and add some good long tube headders. The stock bottom end will be fine.

I'm not going to disagree with any of the advice you offered because you car is well sorted.
I will however offer a few things related to these 400 cid engines. They deserve the rap they get of lo-po smogger engine. The stock pistons are so far down in the bore and the stroke is so short, with the big bore size there is no way to practically get the compression up to a decent level without piston replacement. The junkyard 400 I yanked from a non running 74 Fury literally minutes from going in the shredder. The engine with at least 151k or better was literally perfect on every measurement. Flattest decks and same on left and right banks. Bores were straight and round. The bad is the pistons are .130 down in the bore, impractical to deck that much. I put a pretty heavily modified set of 516 casting heads cut down to a measured 73cc's, only brought my mechanical compression ratio to ~8.5 with no quench at all. With a small cam it would probably run decent, I put a 284/484 Mopar cam in it (because I already owned it). The engine has no bottom end does not come around till 4k rpm, but that is my fault, cam is all wrong.
My suggestion is to use a small performance cam and to advance it 4-8° to build cylinder pressure.
The Hughes whiplash cams are ground very advanced. I used one of their old muscle car cams years ago (similar idea but not as aggressive), and it would have worked well in a smogger engine. I put it in a HP 383 so another bad choice, it ran great but it's appetite for octane was tiresome.

 

[MEV]

I'm not going to disagree with any of the advice you offered because you car is well sorted.
I will however offer a few things related to these 400 cid engines. They deserve the rap they get of lo-po smogger engine. The stock pistons are so far down in the bore and the stroke is so short, with the big bore size there is no way to practically get the compression up to a decent level without piston replacement. The junkyard 400 I yanked from a non running 74 Fury literally minutes from going in the shredder. The engine with at least 151k or better was literally perfect on every measurement. Flattest decks and same on left and right banks. Bores were straight and round. The bad is the pistons are .130 down in the bore, impractical to deck that much. I put a pretty heavily modified set of 516 casting heads cut down to a measured 73cc's, only brought my mechanical compression ratio to ~8.5 with no quench at all. With a small cam it would probably run decent, I put a 284/484 Mopar cam in it (because I already owned it). The engine has no bottom end does not come around till 4k rpm, but that is my fault, cam is all wrong.
My suggestion is to use a small performance cam and to advance it 4-8° to build cylinder pressure.
The Hughes whiplash cams are ground very advanced. I used one of their old muscle car cams years ago (similar idea but not as aggressive), and it would have worked well in a smogger engine. I put it in a HP 383 so another bad choice, it ran great but it's appetite for octane was tiresome.

Totally agree with you, i was trying to give him a reasonable option that would not be a complete waste of scratch and not suggest he find a 440 and start with that. If they are anywhere near .130 down in the hole that makes my recomendations completely worthless.

 

[badvs3vil]

Cant you tell by my ridges that they dont come all the way up?