73 318 upgrade questions

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'73 Root Beer

'73 Root Beer

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Have '73 Swinger 318 904 3 speed 8.25 rear end. Holley Street Avenger 4bbl carb.

In the next few months I am looking at an upgrade. Starting with stock heads cleaned and rebuilt and adding headers. Not looking to blow the doors of things out the gate, but a hwy cruiser. What parts would you change? I am looking at cam, timing chain and gears, valves and springs.

Thanks.
 
I would not add the headers, because for thay are a pain to put on. If you have never put them on an A~body before plan spending some time installing them. Just sayn
 
Change cam and lifters and springs and pushrods.
Rebuild the heads or find the bigger 2.02 valve J heads and rebuild them
Swap to a 4 speed either regular or O/D
Go with 3.21 or 3.55s and a sure grip rear
Throw on some headers or HP Manifolds
 
Do you have a 4 barrel manifold already?

The heads just clean them up and do a little porting on them if you can stock valves should be fine. there's a sticky about porting in the small block forum.

They make a thin head gasket you can grab that and bump the compression up a bit.

I think a cam like this would keep it somewhat mild

http://www.summitracing.com/parts/cca-20-212-2/overview/make/dodge

This cam is one of the most popular around here, its a bit bigger though.

http://www.summitracing.com/parts/cca-20-223-3/overview/make/dodge

Get a nice double roller timing chain for it.

You'll want to do something with the exhaust. There is a few options. Cheap headers are a pain to put in (the engine usually has to be lifted up a few inches and header tubes bashed). there is on set of shorty headers that work but they cost a bit more. I also think I saw someone who ran one magnum manifold and a 360 manifold. You could also spend A LOT of money on some dougs or tti headers that i hear fit the best. do some research in the exhaust forum and see what is best for you. Then of course hook that to a dual exhaust of your choice.

A little bit of converter would help nicely.

You might also consider grabbing some lightweight distributor springs and an orange box if you don't already have those.

It will be like night and day when you finish.
 
Root beer, I've been down this road a few times with 318's. my question to you is, what kind of performance are you looking for. Do you have an idea of what gears you want to run?

I'll tell you what I wouldn't do though for a regular cruiser, Use a 2.02 valve!
Or a 340/360 head until I was looking at mid to low 12's. your stock head and the stock valves can power you into the 14's with 3.55's, and a small cam. No converter needed. Though it would help some.

My last 318 build used the stock pistons in a '78 - 318. It ran a 15.14 OOTB with 3.21 gears on stock tires, Jegs dual exhaust @'2-1/2 inch's hooked up to Hooker headers, an Edelbrock LD4B intake and a 600 CFM carb. The cam was a small Crane at 272/284-.454/.480 on a 112 C-line.

No shift kit, no extra stall converter, no performance distributor or up graded valves.

You can take a 1/2 second plus off the 1/4 time with a XE268 Comp cam (or similar) and a bit more compression. (A light head milling to raise the ratio) move to a set of 3.55 gears.
At this point, while a better stall converter would be a good thing to have, it is not a mandatory thing to have. But I'll bet you be glad when you do.
I seriously suggest headers at this point.

This upgraded set up still runs on 87 octane. You should be able to run a mid 14 easy. It'll be a strong runner.

Look into a Performer or Action plus intake, a comp or Lunati cam, and a MSD or equal like ignition.
 
Shift kit/ a Trans Go
Gears like Yukon or inexpensive
A used intake from the classifieds are cheap enuff. About 1/2 of new shipped.
Make sure your cams durations are split by approx 8-12 degrees.
 
Ok so heres the thought...318
I have edelbrock 4 bbl manifold. Holley SA570 4 bbl carb. 904 3 speed 8.25 rr with 3.21 gear.
looking at
New Edelbrok 60779 heads
5901 Hooker Headers dual exhaust with x pipe and magnaflows.
double gear timing
all I need is an idea for good cruisin cam. This is a daily driver but extra umph never hurt
 
'73 Root Beer said:
Ok so heres the thought...318
I have edelbrock 4 bbl manifold. Holley SA570 4 bbl carb. 904 3 speed 8.25 rr with 3.21 gear.
looking at
New Edelbrok 60779 heads
5901 Hooker Headers dual exhaust with x pipe and magnaflows.
double gear timing
all I need is an idea for good cruisin cam. This is a daily driver but extra umph never hurt
Click to expand...

I would just throw a 4 speed into it since it is already a 3 speed
 
Down the line that will be an upgrade. Previous owner rebuilt the 3 speed not too long ago. Going to do sway control and suspension after upgrading engine. Cam heads timing all original. Even with only 80k on it it is still 40.
 
A good cruising cam....as stated above by rumble, XE268 Comp cam...small, yet fun.
 
The best bang for the buck would be putting 1.88 valves in the heads you have,mill them down to get them in the 9:1 comp range. Keep the intake you have and add headers. Gasket match every thing and run a cam in the 268 int duration range with matching valve springs.
 
Original 40 year old 100K mile bottom end ?
If so you're talking about a boob job for granny. It'll kill her.
Build a entire engine.
 
Mo-Par said:
The best bang for the buck would be putting 1.88 valves in the heads you have,mill them down to get them in the 9:1 comp range. Keep the intake you have and add headers. Gasket match every thing and run a cam in the 268 int duration range with matching valve springs.
Click to expand...

Most results seem to show a mild port job will do better than big valves, and with stock compression pistons it really wouldn't be possible to get 9.0 by milling without other modifications like custom pushrods etc.
 
After much debate with my pocketbook and the fact that yes the bottom end won't match the new top end. Build is on hold...I will however be upgrading to headers and replacing current non crossed dual exhaust.
Anybody running a CMEngine as seen advertised in Mopar Muscle? Thinking for price a swap is more cost efficient.
 
RedFish said:
Original 40 year old 100K mile bottom end ?
If so you're talking about a boob job for granny. It'll kill her.
Build a entire engine.
Click to expand...

:sign5: I think that's my new signature...


Find a good used Magnum engine and just add a 4-bbl. manifold, cam/lifters/springs and shorty headers... should be able to do it for less than $1500
 
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