340 engine build up

[pandamarie]

I have a 71 challenger R/T 340 4 speed 3.91 sure grip.
the block is cracked. I have a new used block forged crank and a set of magnum heads from a 96 318 dakota.
will the old inakes bolt to these heads? the engine in the car now has a set of J heads that have been opened to 2.02 intake 1.60 ex manley stainless valves bowls have been opened and cnc machined. what would be the best combo for a pump premium engine to make as much Hp and torque as possible?

[Dark Horse]

you might want to think about losing the 318 idea,, stick with 340 if you can find another block,if not go with the 360 or big block, i wouldnt use the 318 with the 3.91 4 sp. waste of potential, through a 440 in there, you can find complete running engine for $400 to 600 bucks, and I think that would be a better combo for your 4sp and 3.91sg.. my
2 cents

[Chryco Psycho]

The intake will NOT bolt on but there is a M1 intake that will that accepts a carb for the crate engines
Small block heads basically SUCK the early X & J heads have a very poor exhaust & the newer heads 88 & up have a great exhaust but a restrictive intake port. The Magnum heads will have great velocity & will give better power in the low to midrange but will run out of air at the higher rpm , The X&J are the opposite. The other option is to get a set of the 308 castings from 88-92 , the intake port is still restrictive but larger than the 318 magnum, it has a great exhaust port, & no oiling problems like the magnum heads.
The best fix is to anti up & get a set of W2 heads