The question 400 or 350???

[84 400]

Well since i bought my 84 i have wondered this and since i got some free time tomarrow i would like to lay this one to bed once and for all. When i bought my truck from a guy in texas it had 3 thousand miles on a new motor. The motor was purchaced a while back when the guy was stationed in Georga (in the army). The motor was bought for his then camro project which he sold before the move and never put the motor in. so it was brought from GA to Texas with him and his family. The 84 had a 305 but the guy he bought it from had put a 383 stroker in it. and rebuilt the th350. Eather the 383 went bad or the guy i bought it from did not like it for one reason or the other so he had his buddy pull it out and drop in the current v8 and in return the freind of his got the 383 . Come to find out the guy i bought it from had a fight with the engine builder down in GA about the size of the motor. He ordered a small block 400 from the guy but thought the guy shafted him and gave him a 350. I have done an oil change but found out that the filter for a 350 aned 400 are the same. So were can i get the numbers from to lay this down once and for all. i want it to be the 400 because every one and the mother have 350's (not that they are bad but it is nice to go to a cruse in and say it has a 400.) Also this thing has some power. put the pedel 1/2 way and it will just spin from 0 to 30 mph. It pulls hard and if it is a 350 i wonder what the builder put in it. i would love to have built it my self but i bought the truck for less then the guy paid for this motor. so were do i look for the id code and were can i trace it ?

Thanks
ian