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  • 400 OR 350?

    IM THINKING OF BUILDING A NEW MOTOR FOR NEXT SEASON. I HAVE A 383 NOW THAT HAS LASTED 4 YEARS OF HE$$! IT STILL RUNS GREAT NO SMOKE GOOD OIL PRESSURE. I RUN 7.00HEADS UP1/8TH MILE I SPRAY IT TO DO SO. IM TRYIN TO GET AWAY FROM THE SPRAY TO RUN THE CLASS BUT WANT THE SPRAY FOR INSURANCE. I THOUGHT ABOUT A 400 BUT COULD SAVE A LIL BY FRESHING UP MY MOTOR AN GO BIGGER CAM AND CARB. ANY SUGGESTIONS OR COMMENTS WELCOMED!

  • #2

    Re: 400 OR 350?

    Re: 400 OR 350?

    DITCH THE CAPS LOCK, PLEASE

    Meanwhile, the difference in freshening your 383 versus building a 400 is in the price of the block and pistons (and perhaps some machine work). You need to buy rings, bearings, gaskets anyway, and everything else from your 383 will work on the 400. Cubes are always better.

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    • #3

      Re: 400 OR 350?

      Re: 400 OR 350?

      Sorry bout that! ;D

      Comment


      • #4

        Re: 400 OR 350?

        Re: 400 OR 350?

        It depends on the boat its in if you had to spray the hell out of it to get it there you may not make it with a 400 either. If the 383 was close and you figure picking up 1.6 or 1.7 HP for cube then you will know how close you will be. The 406 should get you there unless the boat is a barge.
        2007 SBN/A Drag Week Winner & First only SBN/A Car in the 9's Till 2012
        First to run in the .90s .80s and .70's in SBN/A
        2012 SSBN/A Drag Week Winner First in the 9.60's/ 9.67 @ 139 1.42 60'
        2013 SSBN/A Drag Week, Lets quit sand bagging, and let it rip!

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        • #5

          Re: 400 OR 350?

          Re: 400 OR 350?

          Its 78 malibu. i dont spray the he$$ out of it. Ive been running the motor for 4 years sprayn for 2years. it hasnt seen but 150shot. I jus been running the he$$ out of it theres a diffrence.lol!

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          • #6

            Re: 400 OR 350?

            Re: 400 OR 350?

            Well you should be able to get there easy with a 400, you are not driving a land barge, lighten the car and all motor Malibu's run ok :
            2007 SBN/A Drag Week Winner & First only SBN/A Car in the 9's Till 2012
            First to run in the .90s .80s and .70's in SBN/A
            2012 SSBN/A Drag Week Winner First in the 9.60's/ 9.67 @ 139 1.42 60'
            2013 SSBN/A Drag Week, Lets quit sand bagging, and let it rip!

            Comment


            • #7

              Re: 400 OR 350?

              Re: 400 OR 350?

              aren't 400 blocks a little bit on the weak side?

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              • #8

                Re: 400 OR 350?

                Re: 400 OR 350?

                Thats what ive been hearing. They dont like heat an dont like rpm.

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                • #9

                  Re: 400 OR 350?

                  Re: 400 OR 350?

                  I'm running a '72 Chevy Caprice 400,4 bolt main and have been trouble free for over 20 years. The previous owner installed it back in '84-'85 when he built the car. He had the block bored .040 to 408 c.i., balanced and professionally built by a man that built tractor pull engines. It still has the stock ho-hum heads but they have been milled to 70 cc with a Edelbrock Performer and Holley 770 Street Avenger. I put a Crane Saturday Night Special cam in a couple years ago, when I did an overhaul to check bearings. I also replaced the stock dish pistons with a set of Speed-Pro flat tops and chrome/moly 1/16" rings.
                  This thing has an amazing amount of torque. I've never had it on a dyno but from all I can gather, various theories and formulas, it should be putting down around 400+ HP. I tested the car with a G-Tech-Pro and liked what I saw but was very skeptical. 0-60 in 3.8 and the quarter in 12.28 secs. Mind you, this is a big car, 3840 lbs with me and a half tank. If the G-Tech was right, I'd be happy, but will wait for this summer to take it to the track when I finish the interior and paint, hopefully.

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                  • #10

                    Re: 400 OR 350?

                    Re: 400 OR 350?

                    aren't 400 blocks a little bit on the weak side?

                    We had a 406 in a Spartan Speedway Limited Late model, at 11.8:1 , run to 8500 for 5 seasons, all we did was a freshen up after the end of every season.

                    While the overall concensus may feel that way, if built right and with good quality parts, they are pretty durable.

                    While that block was magnifluxed, and sonic checked, it was one of a half dozen we had in stock that were equally clean of casting errors.

                    Aftermarket blocks are another option.

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                    • #11

                      Re: 400 OR 350?

                      Re: 400 OR 350?

                      i had a 400 in a 78 camaro. cast crank, trw slugs ,comp roller 680 lift,iron bow tie heads. it ran 6.80s for 4 years no spray.2 bolt block,half full of hard block.(bottom of water pump holes) strength was never a problem. never ran hot with elec water pump and fan.

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                      • #12

                        Re: 400 OR 350?

                        Re: 400 OR 350?

                        IMO, the "run hot" bench racing over 400s is overrated. I've known guys who have them in Jeeps and Land Cruisers. No worse cooling than a regular small-block. I would sonic the block, though, and Hard Blok it a bit if you're worried (then run an oil cooler if you plan to drive it on the street). A two-bolt block tends to be better than a four-bolt and you can upgrade it with aftermarket caps if you want.

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                        • #13

                          Re: 400 OR 350?

                          Re: 400 OR 350?

                          Best reply so far. :D

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                          • #14

                            Re: 400 OR 350?

                            Re: 400 OR 350?

                            Haven't had any issues with my 400 other than getting a good hone and ring seal first time around. No overheating issues and I put a LOT of street and strip miles on it.

                            The 509 casting is probably the best, some like the 817 casting. Either way start with a 2 bolt main block and get splayed 4 bolt main caps installed like DF said. The 511 casting is usually a 4 bolt main -- do NOT use a factory 4 bolt main for a performance engine, the main webbing is weak.

                            It pays to check for cracks and sonic the wall thickness before paying for any real machine work. Honing with a TQ plate is a must and head studs are preferred.

                            If you plan on over 600-700 HP you really need an aftermarket block but some have had good luck plugging the deck and using hard block in the jackets. If you want to go hog wild with an OEM block you will wind up paying as much for machine work trying to make one last as you will for a Dart block IMO.

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                            • #15

                              Re: 400 OR 350?

                              Re: 400 OR 350?

                              Yep. Especially if you don't get a good OE block the first time.

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