318 -> 390 Stroker Advice

[Tim.g.howard]

Hey Guys,

So I got a '73 Challenger (Base model) at Mecum recently and I've been going through what I want to do with it. My goal is to create a very fun street car that will perform well in town and on the freeway but still be a bit of an aggressive muscle car. I won't be taking it to a track for any serious competition.

I was originally looking at an engine swap but recently have been investigating Stroker kits for the original (numbers matching) 318. Not sure there's huge value in keeping it "numbers matching" but I am intrigued by the idea of squeezing 400+ hp from the 318. I've already upgraded the intake and carb and ignition system.

My question is, what are the drawbacks of stroking it to 390? Can the rest of the stock drive train handle that? Will it significantly reduce the longevity of the block or other key components? What experience do folks here have with this kind of mod? Any and all advice welcome and happy to add more details if I've neglected to provide them.

Thanks,

Tim

 

[Chryco Psycho]

This is a no brainer with virtually all upside to stroking Mopars , the rods are very long , the block is tall so going to lighter pistons & longer stroke just makes sense . I have built many strokers both big & small blocks this is a win in every respect . any increase in power will shorten the life of an engine but not significantly in this case .
If I was doing this I would build the 360 , you can get them for almost free & build a 408 stroker , everything is about building a good combo of parts that work together in the same powerband & maximum air flow so good head , intake , camshaft & carb approx 2x the ci so 750 CFM minimum combination is important , I would also look at an OD trans , either the A833OD 4 spd or the 518 auto or a Gearvendor swap for better drivability city & highway . The 83/4 diff will take the power easily .