318 upgrades

Hi fellas. Time to upgrade a few things on the boat, ('70 Fury), and I just have a couple of quick ?'s. (Please hold the "build a 360" thing. With gas almost $6 a gallon here I'd like to be able to drive it The combo so far:
-Bone stock 318. Comp ratio about 8.8:1
-Edelbrock LD4B intake
-Fully rebuilt '88 302 casting heads,(unported), built to stock specs. Got a great deal on these and couldn't turn them down. Figure compression could boost to 9:1 and they gotta be better than the stock 675's on there now.
-Carter AVS from a '70 383 A/T. Flow about 635 cfm.

Now...how much lift can a new, stock '88 valve spring take? Keep it under .450 and I'll be ok? Also looking for cam recommendations. Thinking maybe a Comp 260H. Stock 904 trans and a 2.76 rear gear. Looking just to give it a bit more punch. The big block plans will have to hold till I win the lottery

Thanks and awaiting your wisdom...

keep the cam under 220@.050 you will have to check the max valve lift, use a 4 hole spacer under the carb to help the low end

Those gears are killing any punch you have. I would look for different rear 3rd member. I am guessing its an 8 3/4

In that application I would go with the xe256 or similar lunati voodoo grind.You need short duration with those gears and the weight of the car.The lift associated with cams of this size should not be a problem but I am a small block dummy so check to be sure.

When you do switch heads you might measure your deck height so you can calculate your actual CR for reference but you are in the 7's now.

A heavy C with the combo recommended should run at least 3.23's for gears with a 28" tall tire (23570R15).
Run 2-1/4" dual exhaust Dynomax Super Turbo muffs for good torque response and fuel economy.If not going with headers,use early Dakota Magnum logs or 360 logs.
Recurve the distributor for advance to come in early to move the tank.
You can get amazing fuel economy and performance by using a tuned Thermoquad carb.
When you switch your heads,roller lifters and rockers can help MPG.So can electric cooling fans.The less parasitic drag,the better MPG.
Also it is best to match the convertor to the suggested XE256 cam choice by going one step up in stall speed.

When set up properly with the right engine parts combination,24 MPG highway can be achieved.
.

302s had HORRIBLE valve springs, a stock cammed 80s 318 floated at 4500-5000 RPM. Definitely invest in some beefed up springs.

Rocker arms too, those are pretty weak. Ask me how I know that.

I'll actually be using the rockers and shafts from the '70 heads since they're in such good shape. As for gears, plans are to eventually go with 3.23's Rear is actually an 8.25 and yes it's original, believe it or not. I can't see compression being in the 7's, stock compression listed for a '70 teen is 8.8:1 in every piece of literature I've read. Might be down a bit but that much? Cylinder pressure is really good across the board.

I was thinking advertised was 8.2 or 8.4. At 8.8 I would agree.

I have the same setup as you have except the 302 heads. in a 72 sebring with 3.23 gears.
I have this cam. Very nice.
http://www.lunaticams.com/Product.aspx?id=2340&gid=297

I know you stated to hold the 360 comments, but...

In something as heavy as that Fury a motor with a little more displacement and power might actually yield the same mileage, if not better due to the fact it doesn't need to work as hard.

add a small displacement supercharger or turbo charger and add efi. you'll be surprised at the mileage and power will pick up.

I am with 318 sebring

a voodoo cam and comp 901-16 springs

I am running a roller 60710

258/264
207/213@.050
108/112 icl/lsa
.485/.485 lift

works very good in a heavy 1/2 ton truck with 3.23s,gets about 19 mpgs keeping it down under 2500 rpms

gots lots of mid range,very nice for a 318 IMO

a big car like that I'd use a voodoo 60400 or com XE250, with comp 901 valve springs and stock locks/retainers.

Yeah, I'm starting to look more at the torque heavy cams. This thing will almost never see 5000 rpm so great bottom and good mid is what I'm after.

I can dig the whole 360 argument, hell I've even got one in the garage. Couple of the things that made up my mind though was the cost of a full rebuild for the 360 (which it needs) and that by the time I get the cam I'll be about $500 bucks in for the entire 4 brl/heads/cam thing which is what I can afford for the foreseeable future. As for turbos, superchargers and things...for that coin I'd just go BB

Don't go over 208 intake duration at 50 lift, the VooDoo "00" cam referenced above is the biggest cam you could use in that combo and still get decent mileage and lower end power. Keep in mind that the stock 318 cam intake duration at 50 lift is something like 178 degrees. The abovementioned cam is 30 degrees bigger at 50 lift. The Edelbrock Performer is something like 204 at 50, the Comp high energy 252 is something like 205. I'd also look at the Comp XE 250. Check out the dyno charts compared to the next two sizes of the Comp. Admittedly they are in a chevy engine but the XE250 makes a pretty strong statement.

R.