318 is in a weird position, you could obviously make as much power as any 340/360 to a point. And if 360 were a lot harder or more expensive to get there would be no reason not to start with a LA 318.
To me anyone with a decent running 318 adding mild cam, 4bbl and duals with manifolds or headers is a no brainer 250-280 hp, after that is where things become an issue, head flow becomes a problem especially if you want to stick with stock pistons.
Most people aren't gonna port so 340/360 1.88 or 2.02 are an option especially if adding pistons for cr but most seem to not add cr. Could go magnum heads but might as well start off with a magnum engine. then theres gearing, most only want to run 3.55 which is a compromised gear for a 360 nevermind a slightly higher revving 318 . Since most street guys need idle-5000 rpm powerband 360 gonna give a little more through out that powerband with allowing a little more head cfm and cam and like 3.23-3.55 gears better. 5.2l magnum wouldn't be a bad swap probably same gross hp as a 73 340 but problem is 5.9l aren't that hard to find.
To me I'd rather Magnum 5.9l or 5.2l mild cam, header 4bbl upgrade over stock piston, 1.88 valved 360/318. If being fully rebuilt with higher cr piston than any lA 360 or 5.9L will do especially if your porting or aftermarket heads.
A 318 at that point isn't the best option but can be made to work, but it's more from I want to build something different camp.
It's hard not to say start with a 360 the 42 cid is gonna add a noticeable difference in almost every case, but the 440 guys could say why start with any smallblock or even 383/400.
To me anyone with a decent running 318 adding mild cam, 4bbl and duals with manifolds or headers is a no brainer 250-280 hp, after that is where things become an issue, head flow becomes a problem especially if you want to stick with stock pistons.
Most people aren't gonna port so 340/360 1.88 or 2.02 are an option especially if adding pistons for cr but most seem to not add cr. Could go magnum heads but might as well start off with a magnum engine. then theres gearing, most only want to run 3.55 which is a compromised gear for a 360 nevermind a slightly higher revving 318 . Since most street guys need idle-5000 rpm powerband 360 gonna give a little more through out that powerband with allowing a little more head cfm and cam and like 3.23-3.55 gears better. 5.2l magnum wouldn't be a bad swap probably same gross hp as a 73 340 but problem is 5.9l aren't that hard to find.
To me I'd rather Magnum 5.9l or 5.2l mild cam, header 4bbl upgrade over stock piston, 1.88 valved 360/318. If being fully rebuilt with higher cr piston than any lA 360 or 5.9L will do especially if your porting or aftermarket heads.
A 318 at that point isn't the best option but can be made to work, but it's more from I want to build something different camp.
It's hard not to say start with a 360 the 42 cid is gonna add a noticeable difference in almost every case, but the 440 guys could say why start with any smallblock or even 383/400.
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