Swap or rebuild?

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Freezerman

Freezerman

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Hi guys. I picked up a 72 Swinger with a 318 and Edelbrock 4bbl. Right now it has a 7 1/4 with a 2.76 surgrip. Working on getting stuff together for this winter.
It will have a 8 3/4 with 3.23 gears. I had a 340 years back, I am looking for that kind of performance. I have about $1000 for the engine. The 318 runs good and burns no oil.
I can find 5.9 Magnums with around 120k on them for about $400. Would I be better off working my 318 or trying to drop in a 5.9? :banghead:
I don't want to have to rebuild the bottom end if I get a Magnum. Thanks.
 
Magnum....... no brainer... bigger, more torque, roller cam, better heads...
 
$1000 for an engine is not going to get you to far.....
 
That's kinda what I was thinking but a little worried about spending money on a Magnum and find out heads are bad.
 
I know the budget is kinda low. I was hoping not to do the bottom end if I kept the 318. If it does go over budget I can slow down. It is a project for me and my boys so we aren't trying to hurry.
 
If your turning the wrenches yourself you could wake the the 318 up pretty well. With only $1k in the budget, a top end upgrade may fit the bill. Select your heads/valvetrain combo around your goals & then select the cam to match, not the other way around. I saw Crackedback is kicking around the idea of porting some 302 heads if there was any interest from members, he may be worth reaching out to. The 318 is a fun mill, good luck with your project.
 
I think for $1000 you could do some good bolt ons for now. I'd replace the cam with the small summit brand one, replace the valve springs with Comp 901-16s, upgrade to the MP ignition package, and replace the curent exhaust with cheapie headers and dual exhaust to the bumper. You'll have the gaskets and some engine enamel in there too. You'll have 340 performance and with a pie tin - 340 looks too.
 
So most are saying build up the 318 rather than put in a magnum? I should say the only thing I haven't done is head porting, otherwise I can do the rest.
 
install the 400 dollar 5.9, buy a cheap oil pan, use a cheap intake, like those crosswind things, and done. Don't remove the heads, they prob are cracked, but you wont ever know that, they run forever that way.
 
Unless you have seen it run, I'd avoid the Magnum. But that's just me.
 
moper said:
Unless you have seen it run, I'd avoid the Magnum. But that's just me.
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Yeah, that's a good point, my advise is based on a GOOD ready to install engine with no mechanical issues......
 
So if I can find a magnum that I have seen run or has a warranty try that. Otherwise work the heads and cam on my 318?:banghead: I know the 300 hp 318 threads, I guess I have never had any of my stuff on a dyno so I have hard time judging how much that is. I had a stock 340 swinger with a one step up cam in it, a 18# boost Shelby Daytona, and an SRT4. How would a 300hp or so 318 stack up against them?
 
I believe most 340's from the factory were rated about 240-290 HP. The later models with the lower numbers. A 300hp 318 is ahead of the curve. But bang for your buck in a street car is torque and power curve. Most of us never see peak numbers on the street.
 
Highest rated 340 was the 6 pack one and was rated at 290 HP. Although most would agree, realistically more like 325-330 horse. But everybody lied about horsepower back then for insurance reasons. Does anybody think a 426 HEMI was only 425 HP????????
 
Saetun, I see you have something similar to what I would do with my 318. Do you know how fast yours is?
 
$1000 budget.
Motor you have runs good.... Leave it alone.

Spend your money on the rest of the car:
Front suspension rebuild.
Brakes and brake lines.
Rubber seals to keep wind and water out.
Rebuild the door hinges.
Do minor cosmetics where the car looks nice.
Check and fix everything in the wiring, make sure all gauges, lights etc works per factory.
This is the stuff that most 40 year old cars need.

Having little helpers are fun, I have a picture of my 5 year old grandaughter running the head bolts down on my 340
 
Thanks, we are doing the whole car. My boys are teenagers now so lots of extra muscle:D. Right now we are prepping the 8 3/4 rear and XHD springs, we will stay with the KH front discs. The 318 runs great but needs more power:burnout:. I guess when we pull the heads and see what it looks like I can decide how to do it. I am trying to decide if I would be ahead with a magnum or push the 318 more.
 
Freezerman said:
Saetun, I see you have something similar to what I would do with my 318. Do you know how fast yours is?
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Only have seat of the pants dyno, but im comfortable saying its approx 300hp. Power all the way to 5k then im done. Current 2.76 leave me lacking but 3.23 sure grip sits in my garage. Im very happy but like most here, never content.
 
Engine masters did a stock long block 318 and added headers 4bbl and comp 262, made 282 hp
 
Saetun said:
I believe most 340's from the factory were rated about 240-290 HP. The later models with the lower numbers. A 300hp 318 is ahead of the curve. But bang for your buck in a street car is torque and power curve. Most of us never see peak numbers on the street.
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what you talkin bout willis?
 
bad440 said:
what you talkin bout willis?
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I think he's say in the street your engine rarely see peak hp rpm and that its better to go for low rpm toque cause thats where you do most of your driving at.
 
as the saying goes, a bird in the hand is worth two in the bush. Use the engine you have. I'm sure if you do a Summit cam, intake, headers and some minor head work, you will be really happy with a 318. You know the shape of your engine? why throw money down the drain on another that has unknown issues. Build the 318 and use your spare cash on other odds and ends. It also teaches your kids to be resourceful and use whats at hand.

and a grand wont get you very far by the way unless you slowly gather the parts off here used, minus cam and lifters. and a double roller from Summit for $50. can't beat that. Just be patient and budget build the 318 using the parts you have. crackedback has a thread on how to port 318 open chamber heads to flow magnificent at home. You will probably be pretty happy with the 318. Use a very thin headgasket to bump up compression by the way. If you go completely through that 318, the pricy bits will be machining.
 
Thanks for all the advice guys. Does anyone think It would be worth it to find a 5.9 that I know was running and add an intake and cam instead of working the 318? I can go up some with the budget over time if I need to.
 
Freezerman said:
Thanks for all the advice guys. Does anyone think It would be worth it to find a 5.9 that I know was running and add an intake and cam instead of working the 318? I can go up some with the budget over time if I need to.
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Well, I do.... but seems not many peeps agree... but oh well. The 5.9 magnum will be superior in everyway to your la318. More compression, better flowing heads, roller cam, thinner lower drag rings.... But like I said, this is only a good plan if its a running engine with no issues.. Otherwise hotrodding your 318 isn't a bad plan really, but don't expect too much from it, it has low compression, and is small...but they run good with a mild cam and 4 barrel
 
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