SlinktRR
Well-Known Member
Thought I'd give people thinking about getting a big block stroker another data point to consider. When I bought the roller '70 Plymouth years ago I got a headless 1969 RB 440 short block with it that had sat for many years, mid-project. So I took the 440 out and installed a running 383 to enjoy the car. I put the 440 in a corner of the garage on wood blocks threw a tarp over it and forgot about it. fast forward 6 years and I was ready to see what could be done with that RB.
when I started to turn the motor over on the stand and take measurements I realized that the crankshaft was a 4.15" stroke, so the previous owner had built a stroker already. And then the trick flow 240's came out.. so I knew the engine had to be built to mount these heads. I trucked the disassembled block and parts to the machine shop for cleanup and inspection. The crank was fine, the block was cleaned and the build started.
I went with a used holley street dominator intake ported and gasket matched and a comp cams xs290s solid flat tappet and some old 1.7 roller rockers that the previous owner had in the trunk. The previous pistons were stock MP flat tops (previous heads were probably 906). I couldnt use those with closed chamber 78cc TF heads at near zero deck, so we got custom dished for a 10:1 compression. Heads were cleaned up but the CNC porting from TF was solid.
The builder put it on the dyno, broke in the cam and we ran two intakes (holley SD and trick flow single planes) using a shop 850 holley to compare power. 600hp/625tq for the street dominator, which had a massive torque advantage over the stock trick flow single if you compare area under the curve, but more horsepower potential at 6000+RPM with the trick flow. The holley SD fit under an N96 hood sealed the deal, although I couldnt use my OEM 383 air grabber base anymore. No matter, the engine makes enough power to forget about air cleaners.
What's interesting about this engine is that it sounds exactly the same as my old 383 with a MP484 purple cam and dynomax ultraflos...except it makes twice the power. Good rumble but not ridiculously loud. Same 9" vacuum. Hooker competition 1 7/8" headers fit the heads with angle plugs, so I didnt need to buy a new set of TTI. My only regret is using poly engine mounts, now the chassis shakes way too much. I'm looking at putting in hybrid rubber mounts for the trans mount and passenger side mount, like I saw in a Propwash post from a few years ago, to cut the vibration.
Car runs great. The cooling was a big win, all I changed from my previous setup was an aluminum high flow pump and housing from Mancini. I stayed with a 180F thermostat, stock 7 blade fan and a 26" OEM copper radiator. I lucked out and the combination cools perfectly. I'm pretty sure the key is that mancini pump, because the 383 ran much hotter with the stock iron water pump. Once I plumb the heater box back in it should cool even better.
First time out and riding the wave of torque with the hard shifting 727 was fun. I was up over 100mph in short order without any effort. Whole new world. Once you start, it's a slippery slope and new ideas for enjoyment come up. Now I'm thinking about a 4 speed...
when I started to turn the motor over on the stand and take measurements I realized that the crankshaft was a 4.15" stroke, so the previous owner had built a stroker already. And then the trick flow 240's came out.. so I knew the engine had to be built to mount these heads. I trucked the disassembled block and parts to the machine shop for cleanup and inspection. The crank was fine, the block was cleaned and the build started.
I went with a used holley street dominator intake ported and gasket matched and a comp cams xs290s solid flat tappet and some old 1.7 roller rockers that the previous owner had in the trunk. The previous pistons were stock MP flat tops (previous heads were probably 906). I couldnt use those with closed chamber 78cc TF heads at near zero deck, so we got custom dished for a 10:1 compression. Heads were cleaned up but the CNC porting from TF was solid.
The builder put it on the dyno, broke in the cam and we ran two intakes (holley SD and trick flow single planes) using a shop 850 holley to compare power. 600hp/625tq for the street dominator, which had a massive torque advantage over the stock trick flow single if you compare area under the curve, but more horsepower potential at 6000+RPM with the trick flow. The holley SD fit under an N96 hood sealed the deal, although I couldnt use my OEM 383 air grabber base anymore. No matter, the engine makes enough power to forget about air cleaners.
What's interesting about this engine is that it sounds exactly the same as my old 383 with a MP484 purple cam and dynomax ultraflos...except it makes twice the power. Good rumble but not ridiculously loud. Same 9" vacuum. Hooker competition 1 7/8" headers fit the heads with angle plugs, so I didnt need to buy a new set of TTI. My only regret is using poly engine mounts, now the chassis shakes way too much. I'm looking at putting in hybrid rubber mounts for the trans mount and passenger side mount, like I saw in a Propwash post from a few years ago, to cut the vibration.
Car runs great. The cooling was a big win, all I changed from my previous setup was an aluminum high flow pump and housing from Mancini. I stayed with a 180F thermostat, stock 7 blade fan and a 26" OEM copper radiator. I lucked out and the combination cools perfectly. I'm pretty sure the key is that mancini pump, because the 383 ran much hotter with the stock iron water pump. Once I plumb the heater box back in it should cool even better.
First time out and riding the wave of torque with the hard shifting 727 was fun. I was up over 100mph in short order without any effort. Whole new world. Once you start, it's a slippery slope and new ideas for enjoyment come up. Now I'm thinking about a 4 speed...
