HELP: Cylinder Head and Cam Suggestions for 318

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Shane65

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What's up guys? Hey so wanted to reach out to the experts here... I'm really wanting to wake up my 318 a bit. I've been researching a lot but wanted to reach out and see what you guys think. I'm debating on buying new heads and a cam to make some power, but I do have a set of old 587's that could be rebuilt. Wondering if I should pair those with a 340 cam or see if there was a better route to take? I'm hesitant to go magnum heads. Read a lot of good about TrickFlow heads but looks like they don't stock them anymore... Would eventually like to get this motor somewhere around 350 hp for a fun street car, just looking for the easiest most direct way to get there.

It's a pretty stock 318 in my 68 barracuda. Currently has a 1406 4 barrel Edelbrock Carb, Weiand Stealth intake manifold, and Dougs D453 headers... Stock gears, 255-60-15's out back

I'm fairly mechanically inclined, but I've never taken my engine apart. I would like to do this job on my own if possible, while keeping the bottom end stock for now. What you guys think?

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Good looking 68! You are off to a good start with that intake and headers. I'll let others chime in about heads and cam but look for heads with closed chambers and gasket match everything before installation. I have had good luck with Mr Gasket 1121g .028 head gaskets for some additional compression on 2 builds. You can do this!
 
68 318 should be 9.2 to 1 compression,..id go magnum heads but im not skeered of the rocker system like most folks! but your 587s shaved .050 will work good to for 350 hp! id put a roller cam in it my self but SFT cam will work, id stay away from HFT cams but, 225ish duration @ 50 and 475ish lift, 112 lobe separation for smooth idle and efi, 106 for choppy idle...dwb
 
Put some cam in it. Nothing radical. Then put some 391 gears in it and you will think you have added a hundred cubic inches to the motor.
 
Best advice is read through the small block tech forum… we all have opinions all different, if you can get your hands on one of the older MOPAR engine books and spend some time reading.
 
Shane65 said:
What's up guys? Hey so wanted to reach out to the experts here... I'm really wanting to wake up my 318 a bit. I've been researching a lot but wanted to reach out and see what you guys think. I'm debating on buying new heads and a cam to make some power, but I do have a set of old 587's that could be rebuilt. Wondering if I should pair those with a 340 cam or see if there was a better route to take? I'm hesitant to go magnum heads. Read a lot of good about TrickFlow heads but looks like they don't stock them anymore... Would eventually like to get this motor somewhere around 350 hp for a fun street car, just looking for the easiest most direct way to get there.

It's a pretty stock 318 in my 68 barracuda. Currently has a 1406 4 barrel Edelbrock Carb, Weiand Stealth intake manifold, and Dougs D453 headers... Stock gears, 255-60-15's out back

I'm fairly mechanically inclined, but I've never taken my engine apart. I would like to do this job on my own if possible, while keeping the bottom end stock for now. What you guys think?

View attachment 1716046357

View attachment 1716046358
Click to expand...
Here Is the magic to your answer:

1968 9.2:1 cr 230 hp 318, just for starters. Stock in 1968.

If your valves have not pounded into the 645 open chamber heads with the non hardened seats, then would say the 340 cam will round it out nice.

If the heads are compromised, then upgrade to the 302 closed chamber heads and pick up another 1/2 of a point of compression ratio, and can also go with the thin Mr. Gasket 1121G .028 ths thin head gaskets for even more on the compression ratio bump.

Getting in the area of 9.5:1 cr now. Next add a LD4B 318 aluminum intake manifold and a 1406 Edelbrock carb.

300 + hp here we go.

Don't forget the 2 1/2" full exhaust all the way out the back.

IMG952019030995103236847.jpg



1968 9.2:1 cr factory stock pistons with the light free floating rods.

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782 light weight free floating rods on the left. Heavy 645 rod on the right above.

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You asked for it: Here You Go!

☆☆☆☆☆
 
Last edited:
George Jets said:
Here Is the magic to your answer:

1968 9.2:1 cr 230 hp 318, just for starters. Stock in 1968.

If your valves have not pounded into the 645 open chamber heads with the non hardened seats, then would say the 340 cam will round it out nice.

If the heads are compromised, then upgrade to the 302 closed chamber heads and pick up another 1/2 of a point of compression ratio, and can also go with the thin Mr. Gasket 1121G .028 ths thin head gaskets for even more on the compression ratio bump.

Getting in the area of 9.5:1 cr now. Next add a LD4B 318 aluminum intake manifold and a 1406 Edelbrock carb.

300 + hp here we go.

Don't forget the 2 1/2" full exhaust all the way out the back.

View attachment 1716046596


1968 9.2:1 cr factory stock pistons with the light free floating rods.

View attachment 1716046606

View attachment 1716046607

782 light weight free floating rods on the left. Heavy 645 rod on the right above.

View attachment 1716046609


You asked for it: Here You Go!

☆☆☆☆☆
Click to expand...
Thank you for taking the time to write suggestions. I had a hard time tracking down an LD4B when I was searching a year or so ago however after all my research, many people said the Weiand Stealth is nearly identical to the LD4B so that’s what I ended up with… I’m sure they are within a couple hp from each other…good call on the thin head gasket, I’ll save that part number… I’ve also heard conflicting opinions on 302 heads vs 587’s when combined with 318 block. Some people seem to prefer 587 and vice versa. Do you have experience with both? I did forget to mention I have 2.5” exhaust all the way back.
 
i got a good set of 302 heads i put on a shelf, i got magnum heads for my 318 build cause i wanted better heads!! you can get 350+ hp with 302s but it be easyer with your 587s cc'ed down to what ever compression rato you want! use your 587s less thay wore out, if you buy heads look at speedmaster aluminum!!
 
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xe256h comp cam 212 218@50
340 2.02 heads
airgap
650 750 dp
i ran the 340 cam back in the day in 68 318 727 3.23s with 340 heads
much faster even losing the compression
dc had 340 heads on there 13 sec build
the 110 in at 106 cam will help low end
i went to the hemi grind later with spray to give it bottom end
350hp with the 340 cam not likely
more like 315 320 plenty in a-body street car
 
Shane65 said:
It's a pretty stock 318 in my 68 barracuda. Currently has a 1406 4 barrel Edelbrock Carb, Weiand Stealth intake manifold, and Dougs D453 headers... Stock gears, 255-60-15's out back
Click to expand...

What's the stock gear ratio? Looks like you have a good starting point with the early higher compression motor, intake and exhaust.
If it was me i would do a refresh on the 587s, clean up the ports and mill them down so you don't lose compression, but I like to tinker with stuff.
Easy button would be a set of speedmaster or edelbrock heads. There are better more modern grinds than the 340 cam but be carefull of over camming it. I would be looking for a small solid cam if you have adjustable rockers.
 
I went with TF, Eric Weingartners video about them made the choice easy.. better chamber than pretty much any other choice. They are 4 months back ordered though (I believe the hold up is the valves).. sooner you get in line sooner you get them :)
 
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