need to know how to get 400hp out of 351w?

Discussion in '1965 - 1973 Classic Mustangs -General/Talk-' started by 70stanger, Jul 15, 2006.

  1. Wow, I would have to say that it took me a while to read all this.
    Anywho, I currently have a 92 with a 347. I am trying to buy a 66 and drop it in their. I have a x303 cam, 750 holley, dual plane intake, forged bottom end. I was interested in reading about the AFR heads. I was considering going with the 185 ported, pedestal mount. What is the recommendation from this group? It will be a daily driver, no real strip or racing applications. No AC/ Heater either.
  2. 185 would be a great head for you, provided you have valve clearance.
  3. Max Power,
    I cant remember if my pistons were cut for valve clearance or if it wasnt needed. Is their any way to tell before I pull the heads, or should I just pull them and have a good look? The heads on there now are 351W heads that had a bigger valve job done. I believe it was 2.02 and 1.60 that was done.
    Or would I get about the same performace if I just had the 351W heads ported and polished???
    Bare 185 heads run about 1200 bucks but no clue on a port/polish job for the 351W.
    Any help appreciated.

  4. I would be surprised if you had 2.02s in factory castings. Usually that is too big.

    Aftermarlet heads will pretty much outflow any amount of porting you can do on factory heads. Usually aftermarket heads with 2.02/2.05 intakes will require pistons designed for that. The only way to tell for sure is to bolt a set on and do the clay test for interference. Unfortunately, you can't return heads that have been bolted on.

    Safest bet is AFR 165s with 1.90 intakes, or Performer RPMs with 1.90 intakes. Both are capable of impressive power. I have the 1.90 RPMs on a 393 and they flow enough for my needs.