i bought a 383 from a local guy last week for my sons street 1973 c10. he ran it on the street for a couple hundred miles and decided that $8 a gallon fuel wasn't going to work. He built the motor with around 11.5 to 1 compression. my calculations come in at 11.4. my question is can i run this on the street on premium with these heads and if the tune is right. or should i lower the compression. If the answer is drop the compression, whats the most cost effective way to loose a point of compression. open up the heads combustion chambers. install dished piston(which I'm going to have to re-balance the assembly (looks like the pistons are about 20g difference.) thicker head gasket and ruin the quench. switch to e85. or any other suggestions. this is what i know is in the engine.scat 9000 crank 3.75 stroke5.7 h beam rodsprobe fps .060 over forged pistons 1.425 compression height -4cc flat topshe says the block was at 0 deck heightpatriot 64cc 210 intake headsLunati cam (summit # lun 10120704lk) 110 lobe sep. 504 intake lift 525 exhaust lift. duration at 050 233int 241 ex1.52 aluminum rockersarp boltsperformer rpm intake850 Holley QFT vac sechow do i make a good reliable street motor out of this combo. I also have a another block that is I'm guessing is 30 over.
i am going to start with one question.. can you purchase E85 straight out of the pump in your area.. its not available easily in some areas.. a second question.. end use for your sons truck.. it is really going to be a daily driver.. where he is going to drive back and forth to work.. shopping.. movies.. do stick around.. you will get some answers in a few days..
yes we have e85 in the area. we're in the stl area.he's going to tech school for another semester and its a 3.5 hr highway drive each way when he comes home. At school his job is being a freaky fast delivery guy. He wants to go to gateway and run midnight madness and do some autocross. he also wants it to be faster than his Mazda 3 speed was before he sold it (14.7-1/4mile). which i thought it would be easy to do being and old school guy.I'm starting to lean towards cutting on the heads and opening the chambers a bit. motor only has a couple of hundred miles on it. basically a brand new motor. hate to disassemble it. although the e85 thing is intriguing. My father built this custom truck probably 20 years ago. Last one he'll ever do. the fuel lines all need redone. the tank is good but it wouldn't take much to coat it. the money i saved on other mods would pay for a carb. one other thought. should i change the cam and lower the dynamic compression that way.
I run a 10:1 turbo SBC on E85 and love the power. If I were in your situation I would go the E85 convertion