I have two 68 318 engines,one in my car and one spare.I want to build a 318 over 300 HP and under 400 HP.
I don't want to use Magnum heads.I have 360 heads now with 1.88 intakes and 1.60 exhausts.I want a step by step guide to follow.
The engine in my car made 187 HP at the rear wheels.
Can somebody help me out?
Thanks!

get a 318-390 cu in stroker kit. performer rpm intake, some 1 5/8 tube headers and a mopar 284 .528 lift cam. should be there pretty easy. make sure you have a true 9-9.5:1 compression.

google lists multiple examples.

Either online builds or links to hard copy books on how to do it.

I don't want to stroke it.

Select pistons that will give you a true, calculated 9.5 compression ratio. Run the MP.528 solid cam. Performer RPM intake and a set of cheapo headers. You will exceed 300hp even with your stock stroke 318, however it will like a decent rear gear and torque converter, I would do something like a 3000rpm converter with a 4.10 rear gear.

why not stroke it if your going to change the pistons anyway? a stroker crank is only a few $100 more and then the investment is done.

next option would be to buy a cheap turbo off ebay and bug diszuster to see when his turbo kits will be ready.

spray what you have with some nitrous

if you're reluctant to change pistons because your not rebuilding then its going to be a lot harder to get to 300hp

duplicate

I am going to change piston.Want to be zero deck.

Don't want to seem like I'm pushing it on you but the price to do a full rebuild on stock stroke and building a stroker are basically the same.

The motor in my car now is a 360 based 408 stroker. After feeling the power on tap while still having a streetable motor I will never go back to a stock stroke motor.

EDIT: Besides, no one will know it's a stroker but you

Do you want 300 HP net or gross HP at the flywheel or the 300 net at the rear wheels?
What does the current motor have on it now, IE carb and intake, exhaust, compression ratio and cam?

Stock bottom end,J heads 1.88 int. 160 exh.Performer intake,600 cfm edelbrock,340 hi po manifolds and dual exhaust.3.55 sure grip 8 3/4.Cam is a purple shaft 260/268 duration 430/450 lift

If you run flat tops at zero deck with j heads your not going to have much compression, if your going to run zero deck get a set of closed chamber edelbrock heads.

What application, tire size, gearing, and such (stall speed) so we can estimate the power band required. What octane fuel and altitude to guide us towards a maximum compression ratio?
What sort of budget? any power adders?
How much work like porting, cutting valve spring seats, and such can you do or need to farm out to a shop?
The better flowing heads you start with will make the rest easier.

I have a valiant and used to run a 318 stock heads cut down to raise compression and added a camshaft similar to yours with headers and a good convertor with 391 gears while I don't know what hp it had but would run 14.50 ets quarter mile and would run 13.20 with a 125hp shot of nos.

3.91 gears are in the works.Best 1/4 mile with 3.55 gears is 15.86 at 89 mph

He can hit his power goal without the stroker. More is better but for 300hp this is not a deal breaker.

Either a set of KB 167 pistons or other flattops with 1.81 compression height. That gets the piston to 0.012" below deck. With the Mr. Gasket 0.028 head gasket you have 0.040 squish if you ever decide to go closed chamber. That's with a deck of 9.600.

To build a decent engine you have to take care and the first step is checking your main bearing alignment. Then have the block decks squared up to the crank and to each other. That way you have everything where it's supposed to be.

Piston swept volume is 661.6 cc and to get a true 9.5:1 compression you can have no more than 77.8 cc above the piston. Your 360 heads could be as much as 73cc. You need to cut the heads to 63cc if your pistons have 5cc in the valve notches.

For a camshaft I'd ask Hughes. I'm guessing that something with intake duration in the low 220s would be the ticket.

There are a myriad of 318 buildups online. The one most appropriate for you is this one, no stroker and no Mag heads:
http://www.hotrod.com/articles/mopp-0311-318-engine-buildup-and-dyno-test/

I'm sure that there have been other 400hp 318 articles using 360 heads.

One final observation: You are leaving power and driveability on the table by your choices. It'd be much easier to make 400hp with a 390 shortblock, and it will be much stronger on the street, because the torque curve starts earlier in the rpm range.

R.

I would look closely at your fuel system to make sure the in tank sock filter and lines up to the pump are good and not plugged up
The best way I know of testing the complete fuel system is to be able to fatten the jetting up on teh carb enough to make the 1/4 MPH slow down, if it will your good If it won't, fix it

You will need to run the piston about .040 to .055 out of the hole. Don't be afraid to do it. Use 10:1 compression. Order a cam from Jim at Racer Brown FOR YOUR APPLICATION. If you have manual steering you need Hooker 5204 headers. Power steering...IDK. With a 3.90 gear you can use a single plane intake. Cam accordingly.

For a 318 I'd go Performer RPM and leave it at that. No reason to gamble on a single plane.

Shoot, the mid '70s cast iron 360 EGR 4-barrel manifold was good for something like 390 hp in the Junkyard Jewel article. It's a real high rise design. It's super heavy but then again I got mine for $15.00. It's a spreadbore design so T-Quad or Q-Jet or Street Demon are your choices.

Well, for big bucks you can run the piston out of the block, it'll definitely not be a shelf stock piston, OR, you can mill the heads 0.040 to 0.055 to get the cc down to 63 as I suggested. Take your pick. IMHO milling is more simple and direct.

R.