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304 Performance Build

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  • 304 Performance Build

    I recently had a 304 on the dyno. It was steer, user friendly build for a Hornet hatchback wagon. You can check it out on the forum link

  • #2
    wow. nice torque line.
    Originally posted by Hankrod
    Ristows right.................again,

    Originally posted by Fasts79Chief
    ... like the little 'you know what's' that you are.

    Originally posted by Fasts79Chief
    I LOVE how Ristow has stolen my comment about him ... "Quoted" it ... and made himself famous for being an ***hole to people. Hahahahahahahahahha!

    It's like you're unraveling a big cable-knit sweater that someone keeps knitting...and knitting...and knitting...and knitting...


    • #3
      That is a sweet build!
      Funny how most folks say a 304 is a turd/too small/needs to be swapped for a 360 or a 401.

      I had a Hornet wagon, that will be one fun car w/ that engine!!
      88 GW, 67 J3000, 07 Magnum SRT8


      • #4
        This is the first 304 I built because everyone wants the bigger engines. I really enjoyed this build and I am really pleased with the results.

        This is a very nice small cube engine and should last many years for the customer.

        I did receive a text today, saying the crate showed up to his house, with a picture of the crate next to the Wagon.

        He said he is going to make a post on the other forum on the switch from a 6 cylinder to the 304. It will be a good post and I am anxious to see the end results.


        • #5
          AMC 304, 3.800 bore, 3.44 stroke, ported factory heads, air gap intake 9.72 Compression, Bullet flat tappet hydraulic cam, LS 1.7 ratio, mini shaft conversion

          Sir. Can you explain this "LS 1.7 ratio mini shaft"?
          And how did you get a 9.72 comp ratio? Mill the heads?

          Bullet is just on the other side of town. Bunch of good guys willing to help.
          Especially Kirk, but any will help.



          • #6

            58cc heads, .040 compressed gasket with a 5cc flat top piston. Comes in at 10:1. I made a calculation error.

            I adapt LS mini shaft rockers to AMC bridge heads. They have a 1.7 rocker ratio


            • #7
              Pistons were set at zero deck


              • #8
                Really exciting! and wonder what you've squeezed out of the 360?

                And PM me who you're contact is with at Bullet Cams. It's just on the other side of town for me.
                Thanks for getting back to me.
                Last edited by rockosocko; 04-08-2019, 06:55 AM.


                • #9
                  I built a similar 360 for a customer and it made 437 hp and 458 tq at similar rpm ranges

                  Anyone you talk to at Bullet can help you. I take to whoever answers the phone


                  • #10
                    My very first engine build was a 304 in a 71 Javelin. The motor was really just blueprinted, plus aluminum pistons at stock CR and a Lunati RV cam. It ran on par with any GM 350 with similar mods. This was in any otherwise stock Javelin with drum brakes, a crappy BW automatic, 3:15 rear, and no ability to handle curves.

                    Funny thing - all the machine work was done by Jegs, when they were just a little machine shop and speed shop in Columbus. I did the assembly.
                    Cliff Danley
                    1977 Cherokee S


                    • #11
                      Wow! I assumed that the smaller valves would always handicap a 304. Apparently that is not necessarily true. Nice build.
                      '85 J20 Old Man Truck, bought @ 65K miles - not great, but better than walking.
                      Member, FSJ Prissy Restoration Association
                      High quality junk here: intro thread and slow build thread

                      Did you know? Willys is just Willis spelled differently, but pronounced the same. Neither Willy nor his apostrophe are involved.


                      • #12
                        Heads moves really good air for an 1.84 valve. I did a lot of work on them to see how the engine would do. They were around 230 cfm at .525 and kept going to high 350's I believe.

                        That was with 1.78" tube Doug's headers off my Javelin. A smaller tube header would have made 25 or more ft/lbs of torque.

                        My friend picked up almost 50 ft/lbs with his 351C engine going from 2", 3.5 collector to 1 3/4 primary, 3" collector.

                        I have 1 3/4 Hooker headers for a Wagoneer application I believe for my new dyno headers and I am curious to see if torque numbers go up over previous builds.

                        I have five engines going to the dyno in the next six weeks or so.


                        • #13
                          My ‘77 AMX 304 moved my ‘73 J4000 with tons of loads no problems. Since the rollover I put it in the garage and someone stole the points Dist and carb (joke is on them. I swapped the original carb with a clapped out one just to keep dirt out)
                          In fact, the tweakers stole the distributors, carbs, alternators from every motor in my yard and rolled the new 4.0L up to catch rain through the head ports so it’s toast too.
                          Jeep gauges are for amusement only. Any correlation between them and reality is purely coincidental.