looking to build a 318

[mycharger74]

so a have a 318 in a 74 charger, been looking at swapping heads with a 340 or 360, been finding mixed reviews as to weather its good or bad... some say great others say it'll lower the compression ratio to much... alleviated some by machining but I'm attempting to figure out what is best playing with bigger heads or porting and machining my 318 heads and advise or suggestions. also, i know this is the engine area but..., back in 02 a tree jumped in front of me so im looking for some fenders for the 74 charger... anyone know of any?? thanks

[A383Wing]

The heads will work....but you will loose some compression, and some lower end torque & power with the bigger valve heads....unless you are going racing....stick with the stock heads and do some gasket matching on the intake & exhaust ports

[Rolling_Thunder]

If you plan on having the heads reworked (valve, valve guides, seats, etc) you may as well just get some aluminum heads - they cost about the same when all is said and done. 

If you're looking for stock-ish parts but some added performance i hear the later 318 heads have the swirl type combustion chamber (302 or 308 castings i believe) - they were the last 5.2L head before the magnum family came into existance. 

Do you plan on rebuilding the bottom end? if so then compression can be raised via pistons - some companies make thin head gaskets to help lower compression as well...   

If you're bucks up you can swap on a set of magnum heads but that is a little more involved with the parts

[mycharger74]

thanks for the input, i do want to go more into the engine but I'm not sure if i want to do it now or just play with the upper then latter rework everything.. i know it would probable be more cost effective to do it all while I'm into it but I'm still undecided also any suggestions for a cam? this wont be a daily driver so mileage isn't a factor but i do want to run it on the street in cruises and want to get off the line pretty good i also like top end speed... i know, i kinda want it to do everything... i guess really im looking to build it as a more modern muscle car.. and more advice or  suggestions?  thanks again

[wayfast1500]

What would be required to swap magnum heads? I have a set but thought this wasn't possible due to the oiling system being different? 

[Rolling_Thunder]

Magnum Head Assembly (two required)
Magnum rockers, stands, guide plate, and bolts: MP# P4876050 (eight required)
Special length Pushrods: MP# P5007477
Mopar/AMC lifters: Comp Cams #822 or MP4529220
Magnum head bolts: MP# P4876759
Magnum valve covers
MP Magnum intake
Spark plugs for Magnum heads -  Autolite #3923
Standard LA gaskets
Throttle cable bracket from MP (only used with vertical drilled intakes)MP# P4876850
Throttle return spring bracket from MP (only used with vertical drilled intakes): MP# P4876313

[wayfast1500]

So basically I can get a crosswind intake or the edelbrock and bolt the heads from my magnum 360 on my 318, and use a standard 318 aftermarket cam with longer pushrods? I just want to make sure I understand this before I start ordering parts.

[Rolling_Thunder]

if you have COMPLETE magnum heads (rockers and stuff) then yes - Use Magnum type head bolts (couple are different length than the old 318) and custom length pushrods (specify that you need hollow / oiling pushrods not the standard 318 ones) . You will need AMC lifters (due to the oiling hole needed). bolt the heads down with the crosswind intake and an edelbrock carb...      The throttle bracket can be made to work very easily (i bent mine when i put a crate magnum 360 in my 68 a while back)

[wayfast1500]

Thats pretty cool, I have a complete magnum 360 I plan on dropping in, but for now I may just bolt the heads on my 318.  I figure with headers, the 360 heads, cam, intake, and 4 barrel I should be good for 350-400 horse, I would think.

[pettybird]

Thats pretty cool, I have a complete magnum 360 I plan on dropping in, but for now I may just bolt the heads on my 318.  I figure with headers, the 360 heads, cam, intake, and 4 barrel I should be good for 350-400 horse, I would think.

why bother?  drop the 360 in now and not later??? 

[Dodgecharger74]

JUST DROP IN A 360 STROKED TO 408

[Rolling_Thunder]

Thats pretty cool, I have a complete magnum 360 I plan on dropping in, but for now I may just bolt the heads on my 318.  I figure with headers, the 360 heads, cam, intake, and 4 barrel I should be good for 350-400 horse, I would think.

why bother?  drop the 360 in now and not later???