how do you then know if its a 350 and not a 305? You need to find the casting numbers....

A 383 can have an externally balanced dampner, and trick you. Core pulgs can trick you, thats an old dirt track racers trick. Find a 400 with two core plugs and throw in an internally balanced crank. = looks like a 350

 

Curious why a 383 is being brought into this, cause of the cranks???

 

or throw a 350 internally balanced crank in it

 

we are gonna pull the heads in a week or two so he can have them rebuilt, and we are gonna put his cam in it. not sure how to tell if its a 400? i went over to his house lkast nite to look at the balancer, its not a 400 balancer, cant find the casting #s, dunno. i doubt its a 305,prolly a 350. we will soon see........ole sweet pea sure is purty tho, lmao!!!!!

 

put some double humps or vortec heads on it and that turd will come alive.. ive gotten an edelbrock performer intake id sell ya...the casting number is behind the the drivers side head.

 

If you're going to have the heads off, it's real easy to tell what size engine it is, just measure the bore...

305 = 3.736
350 = 4.00
400 = 4.125

 

Also doubting it's a 400 but as stated, check the casting it's right behind the head on the block. Spray some degreaser or something on it, you'll see it. For casting numbers go here http://www.mortec.com/castnum.htm

Here is a pic of my dads 400
Poor thing was rebuilt, driven 8 miles and been parked for about 5-6 years now.

 

Some 400's had the front and back freeze plugs and a place for a middle one not used. There is only 3 casting numbers for a 400. they are 330817 - 3951509 - 3951511 -.