I just rebuilt and built up my 84 305 n put a lotta goodies in it.
First gen vortec heads
Edelbrock performer intake
Demon 650 carb
K and N cold air intake
Long tuBe headers
HEI distributor setup
Brand new starter
New pistons

The starter will engage but the engine won't turn overm
I've got 4 spark plugs out so its not a compression problem.
The battery is at 18 volts so its fully charged.
No ground wire problems.
Please reply asap or just text 4058089453 cause I'm goin crazy!!

 

Can you turn it over by hand? Also why is your battery charged to 18v thats a bit high dont you think?

 

Do you have the correct starter/flywheel installed?

 

check the bolts on the flywheel if you put on the wrong ones (too long)they will sit against the block and the engine will not turn

 

sounds like you don't have the right starter on.. one will have the bolt holes side by side and the other will have it staggered

 

probably one of the above answers but something stupid ive done was over tighten the rockers and once the pushrod bent to touch the head it wouldnt turn any further. i dont know if you set preload, but hey, stupid mistakes help others learn so i guess my mistake isnt a total loss lol. that was a 'it wont turn by hand' situation so i dont even know if the starter being used would be different.

 

try to turn it by hand, if it rotates then its the starter. I just finished an engine swap on a truck and the starter worked for a few cranks then it would engage but not turn over. Turned out the started was junk. If it isnt that, then your jammed up somewhere

 

also when I build an engine, everytime I install the crank and pistons I rotate the assembly, cam and timing chain, rotate, valves and lifters I rotate, I know it takes a few minutes longer to finish but then I know that everything is moving right away and if something binds up I know where and I don't have to tear my engine back down to find and fix