Hello everyone! I have a 1973 d100 project I'm working on. Has a 360 with a 727 behind it, was a two barrel i have since added a edelbrock air gap intake a quick fuel 750 headers and a small cam. Back in February I called a couple shops to get pricing on getting the heads rebuilt bigger valves etc. Three different shops told me they couldn't do that kind of work or didn't have a technician at the time. The few that I did find was giving me quotes of $800 plus parts. So I just went ahead and bought the cheaper speedmaster heads. Since then the shipping date has changed about four times now and they are telling me they probably won't ship till April 18th, and i wouldn't be surprised if it changes again. My question is should I just pay the difference and get the edelbrock rpm heads that are in stock? Are they pretty much the same? The bottom end of this engine is stock I'm not trying to make a whole lot of power with this truck. The cam is a small cam that I really only replaced because when I removed the intake one of the lobes was questionable. It's a sum-1789 with a 454 lift hydraulic flat tappet. I already have the 1121 mr gasket head gaskets and arp head studs for the edelbrock rpm heads.
Edelbrock rpm heads
- Thread starter Sam_318
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Ironmike
Well-Known Member
Whatever way you decide to go, they will have to be gone over by a good machinist. Never trust "out of the box".
middleagecrisis
Well-Known Member
Look in the performance parts classifieds, a set of speed masters and Edelbrock RPM heads for sale.
With your combo you won't notice any difference between the options you've presented. Either of those heads will make a difference you can feel compared to stock heads.
The much bigger things you need to consider are the rest of the combo.
What torque converter, what rear end gears?
The much bigger things you need to consider are the rest of the combo.
What torque converter, what rear end gears?
340sFastback
Well-Known Member
I don't think you need bigger valves in those stock heads for what your doing. Good 3 angle valve job minor bowl blending should be sufficient. Also pay attention to head gasket thickness. You want a thin head gasket to increase compression.
I agree. I would not mess with modifying the old iron heads for sure.
With your combo I wouldn't expect to feel a huge difference with the eddy/SM heads but they will make at least equal or slightly better low end (with the smaller chambers) and will definitely hold an advantage as the RPMs climb, and will be upgradeable as time passes.
With your combo I wouldn't expect to feel a huge difference with the eddy/SM heads but they will make at least equal or slightly better low end (with the smaller chambers) and will definitely hold an advantage as the RPMs climb, and will be upgradeable as time passes.
Ironmike
Well-Known Member
Not to mention they would take 50-60 pounds off the nose.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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With that combo, 63cc heads and .028 gaskets, your compression is likely gonna be near 8.9 which would be a good gain.
Unfortunately;
with a straight-up Ica of 66* you're gonna lose Cylinder pressure compared to stock. and, if you advance it, you'll lose effective overlap, which is already low, and all of it is below .050.
Either way, your bottom end is gonna be softer compared to the stock cam, especially if you are running the stock convertor, hiway gears, and tall tires..
Because of the way all that plays out,
I might;
advance the cam,
leave the 360 heads on it,
get a higher stall convertor,
and some performance gears.
This will be money way better spent.
But
If you plan to run lots of hiway miles,
For my money,
I'd forget all that, and just put an overdrive in it, and gear the crap out of it. In this way it may be fine with whatever stall it comes with. And, it will jump off the line with way more authority, daymn the alloy heads.
The Mopar overdrives have a .69od,
allowing gears like 4.30s, to still cruise comfortably with taller tires, like 29s; making the starter gear 10.5 (with a 2.45 Low). That will rocket you off the line; and those will still cruize at 2235 in lock-up mode, which is where mine cruizes at; and I got no complaints. At that rpm, you can almost get optimum ignition-timing into the factory distributor for best fuel economy.
In a pick-up, this should almost be a bolt-in, with the major change being a shorter driveshaft.
If you already have an 8.75, you're in business.
This is My Opinion.
I'm NOT telling you what to do.
I'm telling you what I would do for most bang for MY money.
Well, if I'm going there then I would for sure pump up the compression, install the alloy heads, and get me a bigger cam, and probably Ladder-Bars too, lol. Jus saying ...........
Unfortunately;
with a straight-up Ica of 66* you're gonna lose Cylinder pressure compared to stock. and, if you advance it, you'll lose effective overlap, which is already low, and all of it is below .050.
Either way, your bottom end is gonna be softer compared to the stock cam, especially if you are running the stock convertor, hiway gears, and tall tires..
Because of the way all that plays out,
I might;
advance the cam,
leave the 360 heads on it,
get a higher stall convertor,
and some performance gears.
This will be money way better spent.
But
If you plan to run lots of hiway miles,
For my money,
I'd forget all that, and just put an overdrive in it, and gear the crap out of it. In this way it may be fine with whatever stall it comes with. And, it will jump off the line with way more authority, daymn the alloy heads.
The Mopar overdrives have a .69od,
allowing gears like 4.30s, to still cruise comfortably with taller tires, like 29s; making the starter gear 10.5 (with a 2.45 Low). That will rocket you off the line; and those will still cruize at 2235 in lock-up mode, which is where mine cruizes at; and I got no complaints. At that rpm, you can almost get optimum ignition-timing into the factory distributor for best fuel economy.
In a pick-up, this should almost be a bolt-in, with the major change being a shorter driveshaft.
If you already have an 8.75, you're in business.
This is My Opinion.
I'm NOT telling you what to do.
I'm telling you what I would do for most bang for MY money.
Well, if I'm going there then I would for sure pump up the compression, install the alloy heads, and get me a bigger cam, and probably Ladder-Bars too, lol. Jus saying ...........
I appreciate all the responses, this engine is not gonna stay in the truck. I would like to eventually put a big block mopar when I can afford it lol. The 360 that's in it right now is gonna get pulled and get rebuilt to suit the heads better, and put into my valiant. I just really wanted some opinions on the two heads if one was better then the other. Really trying to take advantage of this nicer weather before it gets too hot here in texas to wanna be outside working on it being that I don't have a garage. I think I'm just gonna pay the difference and get the edelbrock heads I'm almost certain the shipping date is gonna keep changing. That bs happened the last time I ordered from jegs back in 2018 and now I'm reminded why I stopped ordering from them, that and not too mention there's a summit racing about 45 minutes away from me.
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