Which heads?

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BsB Duster

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So I am trying to get an engine together for my sons 67 Dart. The original 273 engine is seized after sitting for years, so I bought a good used 1976 360. I bought a summit 6901 cam, performer intake, hooker headers, and speed demon 625 carb. Should I use the 67 273 closed chamber heads to boost compression or should I use the original 360 heads? I have blown up my brain trying to figure this out. I’m not changing pistons or anything like that just want the best bang for the buck. Thanks
 
I don't think the 273 heads would be a good choice on a 360 but you can run them if you're on a tight budget. You might look into some good aftermarket heads, iron or aluminum. The Trickflows are probably the best but there are less expensive heads that will work well.
 
BsB Duster said:
So I am trying to get an engine together for my sons 67 Dart. The original 273 engine is seized after sitting for years, so I bought a good used 1976 360. I bought a summit 6901 cam, performer intake, hooker headers, and speed demon 625 carb. Should I use the 67 273 closed chamber heads to boost compression or should I use the original 360 heads? I have blown up my brain trying to figure this out. I’m not changing pistons or anything like that just want the best bang for the buck. Thanks
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If the engine was seized from sitting, are the heads any good? If they need rebuilt, that's going to add up quick. I'd stick with the 360 heads if it was a running engine. That cam isn't much bigger than stock and with the pistons still down in the hole, there's going to be little to gain with the 273 heads. The open heads will flow better anyway, and 360 heads should have larger ports and valves too (I think).
 
BsB Duster said:
So I am trying to get an engine together for my sons 67 Dart. The original 273 engine is seized after sitting for years, so I bought a good used 1976 360. I bought a summit 6901 cam, performer intake, hooker headers, and speed demon 625 carb. Should I use the 67 273 closed chamber heads to boost compression or should I use the original 360 heads? I have blown up my brain trying to figure this out. I’m not changing pistons or anything like that just want the best bang for the buck. Thanks
Click to expand...
Best wishes for you and your (how old?) son with a 360. Hopefully he is responsible with power (see Mustang crashing videos)

My low-level recommendation (KISS) is to either recondition the cylinder heads, or buy the chinese Speedpro/Speedmaster aluminum heads assembled & have them checked out at a machine shop.

First option, call up summit,
get valve spring recommendations,
the giant c clamp removal/installation tool ($100),
remove valve springs and retainers
(AND KEEP TRACK WHICH VALVE/SPRING/RETAINER GOES WITH WHICH HOLE ON WHICH HEAD),
bring the heads (bare) to the machine shop, have the shop perform a valve job,
ask about hardened seats, ask about valve condition,
have the shop verify valve spring retainers or replace them,
install valve seals (Viton??), and
either they assemble the heads for you or you take the clamp are reassemble them yourself after one more extra cleaning, drying, and then lubrication.

after these two choices, and if unlucky, during these choices, cylinder head options can be expensive.
keep it simple sir!

Another option is the dodge 318 (1980's) '302' cylinder heads refreshened-without porting they would govern the rpm's of your son's driving due to less air flow but increase torque with the smaller, closed chamber, cylinder head. Mopar official would port them for you for more air flow.

the 273 cylinder heads MIGHT not bolt up to the later LA if it is an early enough engine as I understand the members here on FABO SBM
 
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greymouser7 said:
Best wishes for you and your (how old?) son with a 360. Hopefully he is responsible with power (see Mustang crashing videos)

My low-level recommendation (KISS) is to either recondition the cylinder heads, or buy the chinese Speedpro/Speedmaster aluminum heads assembled & have them checked out at a machine shop.

First option, call up summit,
get valve spring recommendations,
the giant c clamp removal/installation tool ($100),
remove valve springs and retainers
(AND KEEP TRACK WHICH VALVE/SPRING/RETAINER GOES WITH WHICH HOLE ON WHICH HEAD),
bring the heads (bare) to the machine shop, have the shop perform a valve job,
ask about hardened seats, ask about valve condition,
have the shop verify valve spring retainers or replace them,
install valve seals (Viton??), and
either they assemble the heads for you or you take the clamp are reassemble them yourself after one more extra cleaning, drying, and then lubrication.

after these two choices, and if unlucky, during these choices, cylinder head options can be expensive.
keep it simple sir!

Another option is the dodge 318 (1980's) '302' cylinder heads refreshened-without porting they would govern the rpm's of your son's driving due to less air flow but increase torque with the smaller, closed chamber, cylinder head. Mopar official would port them for you for more air flow.

the 273 cylinder heads MIGHT not bolt up to the later LA if it is an early enough engine as I understand the members here on FABO SBM
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He is plenty responsible to handle this car. I’m not trying to make a ton of power just thought with the small cam I chose that the small chamber heads might make a little less doggy engine. The 273 was rebuilt before setting up for 18 years the heads appear to be fine, the engine just has rust in the cylinders from sitting so long. If the 360 heads are the best option I will put matching springs on them and run em. He is planning a 5.7 Hemi swap in the future anyways this why we are keeping this one as cheap as possible.
 
dart_68 said:
I don't think the 273 heads would be a good choice on a 360 but you can run them if you're on a tight budget. You might look into some good aftermarket heads, iron or aluminum. The Trickflows are probably the best but there are less expensive heads that will work well.
Click to expand...
Thanks for the response
 
BsB Duster said:
He is plenty responsible to handle this car. I’m not trying to make a ton of power just thought with the small cam I chose that the small chamber heads might make a little less doggy engine. The 273 was rebuilt before setting up for 18 years the heads appear to be fine, the engine just has rust in the cylinders from sitting so long. If the 360 heads are the best option I will put matching springs on them and run em. He is planning a 5.7 Hemi swap in the future anyways this why we are keeping this one as cheap as possible.
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That's good to hear. I wasn't that responsible at 20. I think your camshaft will alleviate the 'doggyness.'
Also you could mill the heads .040" and then the intake to match which would reduce the chamber to (maybe, possibly) about 66cc which ALSO will alleviate the 'doggyness.' My apologies for offending you. I believe that you probably have the '675' cylinder heads used both on 360's and 318's with your 360 being a late 70's block.
 
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Use the 360 heads have them milled and use the thinnest head gaskets you can buy. 65'
 
agree with rumble
cut the heads and manifold face, mr gasket .028 gasket
but
valiant racing
too small for what?
back and forth to school and paying for his own gas they would be fine
small 318 tq will get the best mileage
 
greymouser7 said:
That's good to hear. I wasn't that responsible at 20. I think your camshaft will alleviate the 'doggyness.'
Also you could mill the heads .040" and then the intake to match which would reduce the chamber to (maybe, possibly) about 66cc which ALSO will alleviate the 'doggyness.' My apologies for offending you. I believe that you probably have the '675' cylinder heads used both on 360's and 318's with your 360 being a late 70's block.
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Finally able to reply to everyone. My phone is acting crazy. If I mill the heads .040 how much do I have to mill the intake? Thanks
 
that 6901 is not as small as you might think;
276/288/114 advertised;
218/[email protected]
.441/.441lifts
"Fair-smooth idle, low-midrange power. Works with stock-2,000 stall, 9:1 and higher compression, and gearing."

the only thing small about it is the lifts.218/228 is a nice size tho.
 
BsB Duster said:
Finally able to reply to everyone. My phone is acting crazy. If I mill the heads .040 how much do I have to mill the intake? Thanks
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There is a formula in the MP books. I do not have it on hand or in the memory.
AJ/FormS said:
276/288/114 advertised;
218/[email protected]
.441/.441lifts
"Fair-smooth idle, low-midrange power. Works with stock-2,000 stall, 9:1 and higher compression, and gearing."

the only thing small about it is the lifts.218/228 is a nice size tho.
Click to expand...
I e used this duration before a have found it really good and best with 3.21 or better gearing w/stock to slightly bigger tires. IDK how it would work with a 2.96 or 2.76 gear. Maybe a bit sluggish out of the hole.
 
rumblefish360 said:
There is a formula in the MP books. I do not have it on hand or in the memory.

I e used this duration before a have found it really good and best with 3.21 or better gearing w/stock to slightly bigger tires. IDK how it would work with a 2.96 or 2.76 gear. Maybe a bit sluggish out of the hole.
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The car has a 4.30 8 3/4 so gearing shouldn’t be a problem although we are planning to put 3.23 in it ASAP. Lol
 
Don't forget to address the drivetrain balance issue. You'll need a correctly weighted torque converter or flywheel.
 
Demonic said:
Don't forget to address the drivetrain balance issue. You'll need a correctly weighted torque converter or flywheel.
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Good mention. Being he has an automatic, I’d do and have done a B&M flexplate.
BsB Duster said:
The car has a 4.30 8 3/4 so gearing shouldn’t be a problem although we are planning to put 3.23 in it ASAP. Lol
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I really would not go any lower numerically.
Whatcha got for a tire size?
 
rumblefish360 said:
Good mention. Being he has an automatic, I’d do and have done a B&M flexplate.

I really would not go any lower numerically.
Whatcha got for a tire size?
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It has a brand new set of 275/60/15 drag radials. Will the B&M flexplate allow me to run the neutral balance 273 convertor? I can get a stall if it will benefit me that much more, although I need to check the 904 spline count because I think a 1967 904 is different from 68 and up.
 
BsB Duster said:
It has a brand new set of 275/60/15 drag radials.
Click to expand...
Whoa that’s a big tire for that cam and stock stall
Will the B&M flexplate allow me to run the neutral balance 273 convertor?
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Yes, that is a zero balance converter or neutral balance.
I can get a stall if it will benefit me that much more, although I need to check the 904 spline count because I think a 1967 904 is different from 68 and up.
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I had that exact issue with my wife’s’67 Cuda and the 904 I came with. It had the odd spline count. I found it impossible to get even a replacement converter never mind a performance unit.

So! Down the block from me (Literally) is a converter shop called Pro Torque that custom re stalled and built up the OE converter. Expensive but worth it. Lots of ceiling room. Perhaps that idea is a workable solution for yourself. A capable & Local shop?
 
rumblefish360 said:
Whoa that’s a big tire for that cam and stock stall

Yes, that is a zero balance converter or neutral balance.

I had that exact issue with my wife’s’67 Cuda and the 904 I came with. It had the odd spline count. I found it impossible to get even a replacement converter never mind a performance unit.

So! Down the block from me (Literally) is a converter shop called Pro Torque that custom re stalled and built up the OE converter. Expensive but worth it. Lots of ceiling room. Perhaps that idea is a workable solution for yourself. A capable & Local shop?
Click to expand...
So I bought that tire hoping to compensate for the 4.30 gear, was that a bad move? I will contact them and see what they can do with the stock convertor if I do have a 67 trans.
 
67 273 heads flow about the same as late 360 heads, up to .400 to .500 lift about 180 cfm vs about 190 cfm. But they have the small ports so the Performer will work. There is more potential with the 360 heads. But the 66-67 273 heads are not as bad as one would think considering the compression boost. From 73cc to 65cc unmilled, or 64.7cc to 57.3 milled .040" and .038" on the intake side.
 
BsB Duster said:
So I bought that tire hoping to compensate for the 4.30 gear, was that a bad move? I will contact them and see what they can do with the stock convertor if I do have a 67 trans.
Click to expand...
That tire and 4:30’s? I’d be OK with that. I’m doing that now but with 4.88’s in my Duster.
MY Cuda has 4.10’s and 255/60/15’s.
It’s all in the same ball park-ish area.

Contact who? Pro Torque?

Click this then if no one is local or close. —> http://protorque.com/
 
66fs said:
67 273 heads flow about the same as late 360 heads, up to .400 to .500 lift about 180 cfm vs about 190 cfm. But they have the small ports so the Performer will work. There is more potential with the 360 heads. But the 66-67 273 heads are not as bad as one would think considering the compression boost. From 73cc to 65cc unmilled, or 64.7cc to 57.3 milled .040" and .038" on the intake side.
Click to expand...
I read that somewhere else just can’t remember where. Maybe with the small cam that I have this would be the better option. Decisions Decisions lol
 
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