Any suggestions on breaking in my engine????? Its a 383. 4340 crank, H-beam rods, 9.8 to 1 compression, speed pro pistons, LT4 hotcam, canton stroker oilpan/pickup,and ported vortec heads. I'm going to use mobil 5W-30 oil. just want to make sure I protect my investment. Thanks!

 

I would use the cheapest oil that I can find, start up the motor...let everything come up to temperature, make sure no over heating problems, no leaks, and oil pressure is good. Drain the oil(don't change the filter) fill it up again. Then take her out and have fun. Wouldn't worry about the 500 mile break in crap that manufacturer's recommend. But I would change the oil and filter after a couple hundred miles, put in your mobil synthetic and you should be good to go....and definatelly by then you will know if you are going to have any problems...good luck

 

I would not put in any raditator fluid (just use water) for the first start up. I had to flush mine several times. Then add coolant. In my case since i had to take the motor back apart 3 times i went through 6 bottels of coolant.

 

I would definatly give it about 3-500 miles before I do any WOT runs...and I wounldn't switch over to synthetic oil until you have least 2500 miles on it....otherwise, that motor will "drink" oil..When I got my 383 short block back from Nu-Tek, Nick said that he would put at LEAST 300 miles on it before you hit WOT...and use a 30wt oil.