You can get a TBI kit for under a grand. you'll need a cam and head work done though. Also that 904 is going to be expensive to build up.

Your best bet is to find a 360/727 combo and swap that in with a cam, intake, head work, etc.

 

300-400 hp out of a 318??? Good luck with that, you're going to need it! The 318 was designed as mopar's workhorse engine and while a lot of things will transfer over from a 360, it just doesn't have the displacement to get that kind of horepower without sinking thousands of dollars into it. If you want power like that I agree with Tim that you should just swap it out for a bigger engine and build that one.

 

yeah a crate 360 would be good cammed up . shop around see whats on ebay or other for sale sites . do Indy do aerohead small block heads ? what carby & exhaust do you have ? because to make 350 + hp you'll need a set of headers & 2 1/2 exhaust with free flowing mufflers , a decent inlet manifold Holley street dominator single plane or eddlebrock air gap with a 600 -650 carb . cam , lifters , springs timing chain . you can definitely make the power but costs may & will blow out . if you really shop around you could buy a motor & box already done 2nd hand . because you'd need a stall converter & this & that for the 904 as well to make that power . yep you can make the power for sure but to do the gear box as well for $4000 is pushing it . because the ol 318 needs higher compression pistons to make the cam work . the cleaning & machining would be about $1000 at leased including you heads . i was gonna spend $5000 on my 318 & found a 383 big block for $3500 running with a 727 . & it still wasn't enough .

 

just found this thanks Tim ( tbi ) green bay parts world 318 . i tryed to cut & paste but didn't work .
i was just on a allpar site & they had very good tech article about increasing power on a budget for the 318 . using a 340 cam ( which you don't need a stall converter ) which also is a $35 option for tbi kit above . with bowl work & mild porting , 360 inlet valves , .020" shaved of the 318 heads extractors & twin exhaust , 550 - 650 carb & dual plane manifold i think that would get your 300 hp + depending on the compression ratio & timing .

 

?
http://greenbaypartsworld.net/websto...iew&page=C318B



http://www.allhttp://www.moparmuscle...opar/4bbl.html

 

???
http://www.moparmusclemagazine.com/t...ons/index.html

 

Here is my recipe:

Shave the heads .020''
Have a machine shop replace the stock 1.78 valves with 1.88 valves
Retain stock exhaust valves if you choose to go with headers
Replace pistons with minor overbore (if necessary)
Use a street cam good for low and mid range driving power (any Comp Cams High Energy cams will work)
Use any dual plane intake
Holley single inlet 600cfm vacume secondary
Dual exhaust

I have seen this build done. I also plan on doing it myself once I make the extra money.
It is less expensive than a 360, a little better on gas, and will net you about 335hp at the flywheel.
What most people dont know is that 904s with 318s came with a 2400 stall converter stock. If you dont believe me, look at the chassis manual.
Use moderate gears, and your car should fly

 

I'm also gonna bowl port mine & open the push rod pinch , lightly run all over the port & blend the valve guide boss .
i already have new 1.88 360 inlet valves , I'll have them back cut & stock 318 exhaust back cut & get a 3 angle valve job .
I'm just using a 340 cam that comes with those green bay rebuild kits & i want to use those silvolite pistons as well . i really want at leased 9.5:1 comp .
i also have a 904 thats bolted to the 318 now .
I'm putting mine in my Nissan 720 pickup 4x4 that i have given to my girlfriend . she'll have a ball in that thing .

 

forget that 360; there's plenty of 300-400 HP 318 builds in recent magazine articles.

 

Hot rod mag has an article on making a 318 put out 400 hp and you can also check out Hensley performance they have a 402ci 318 thats close to 500 hp.