opinions on this Internal Combo

Discussion in 'Fox 5.0 Mustang Tech' started by Black331Stang, Dec 7, 2003.

  1. im all set for my stroker but i was just wondering what some of your opinions would be on some of my questions. this will be on a 347 or 331 stroker. im leaning towards a 331.

    1st off....heres what im looking for....Good Driveability, 375-400 RWHP, MAYBE some nitrous 100 shot at most..and rarely.....street drieven with occasional track use...probably only 5 times a season.

    -ok now would i be ok with a Cast Steel crank or should i go Forged??

    -what is better/the major differences/what would suit my needs...H beam or I beam rods?

    -one set of rods says 5140 forged I beam and teh other 4340 forged H beam...im thinking teh 4340 is alot better

    -does a 1 piece billet steel main support sound good?

    -anyone ever hear of the brand KAT for internals? i dunno if it was just a mistype mean SCAT :shrug: ....that was listed on a shortblock

    -not into far detail but would u guys go with 331/347...i dont think the tradeoffs are worth it for a 347...less life, chance of burning oil on startup, only an average 25 Hp differnce

    -and finally,this will be on a brand new Ford Block. With the block hold this motor even with the 100 shot of nitrous? assuming im making 400RWHP? and ive head sportsman hold up to 650..is this accurate?

    thanks in advance for any help.
  2. Why stroke? Just put a basic 302 with forged pistons together with good heads and a 6psi blower. 400RWHP, 20+MPG, emmisions legal. High HP NA cars almost always have too many trade off to be a lot of fun daily driving between gears, tune issues, idle quality and low speed performance.


  3. Brian
  4. all forged eternals, much stronger then steel.. 4340 rods, for sure.. you'll probably hit like 340 at the wheels with a power adder it only goes up.. 331 for longer life, dont have to worry about the oil consumption myth, great in the higher rpm band, plus its a great daily driver, money spent wisely in my eyes..
  5. if you use a stock block a main girdle is needed for strength. if you use the 302 sportsman block you dont need a girdle. if you plan to keep the shift point under 6500 then cast steel crank and 5140 i beam rods are more than fine. but if you plan to spin it above 6500 then the forged crank and 4340 h beams are manditory. I prefer stocker kits with standard bore pistons. over bore types like .030" over thin the cylinder walls too much and make them weak. so I like the 342 kits, basically a 347 kit with std bore pistons.