block questions 1964 390October 2 2017 at 10:27 PM
javier (Login Ranchopower)
have a 64 390 block std bore that has the extra main webbing and could be cross bolted what are these blocks good for as far as bore size goes?
good for a 4.130 bore?
Don't take a chance on ruining a good block.
|October 3 2017, 4:09 AM |
Go only as far as you need to, to correct cylinder flaws. 4.080" is plenty.
I would rather even keep it stock bore if its straight and no taper, put a 410 crank in it
|October 3 2017, 5:23 AM |
with after market long rods and short light thin ring pistons, weld up the port pinch and drill the pushrod holes so you can widen the he head and intake manifold ports. MY intake ports are 1.45 wide on both because the previous owner of the intake widened the pinch to allow it, that and the 12° angle mill on the heads really made the 394 turn on, I would love to put in a 4" stoke crank with 6.8 rods and 1.34 CH metric ring pistons. The 394 runs like a cat with turpentine on his tail ! Imagine a 410 with Blair's BBMs? The stiffer bores are worth it, 4.07 on mine 4.08 max on any 390 bore core block.
|October 3 2017, 8:33 AM |
yea there is much truth in that statement just build what you have with long arm for torque and have a chassis that will hold up to it.
you drilled pushrod tubes out and pushed in sleeves to widen?
The pushrod pinch is in the intake, you can jB weld and weld the side you want to go
|October 3 2017, 10:06 AM |
and redrill the port pinch for the pushrods. I have used a matrix on a Port-O-Sonic to with aluminum dust and Devcon to fill the holes I wanted to modify, welded the side redrilled the pushrod hole and the ground on the matrix of dust and Devcon to make the port just under 1.5 inches at the pinch and them widened the "inside" of the port to widen it and smooth the turn into the chamber rolling it into the short side to make port window bigger and less turbulent.
I used to do it on 340 Mopars all the time . Mopar's W2-5 head has that from Direct Connection or Racer Brown.
Don't get fascinated on 428 bore size
|October 3 2017, 4:17 AM |
Minimal overbore for cylinder wall strength, go for stroke instead. Sounds like a Facebook question, where you will get those guys who claim any block will go, done it a hunnert times....
|October 3 2017, 4:34 AM |
was just wondering if there was enough meat in there, have not sonic checked it out yet is still std bore.
yes would not have an issue using the smaller bore since the subject is always floating around figured it would
be an easily answered question. thanks for the replies
|October 3 2017, 5:06 AM |
I have had several 390 - 428 bored blocks. had great service out of them, only failure I ever had was a 30 over 428.
|October 3 2017, 11:03 AM |
Not very likely to leave much wall thickness
|October 3 2017, 4:56 PM |
unknown cyl wall thickness, compression is 11.0 or so, buzzed to 6000 + regularly, took it to dragweek twice and drove it there from northern mn. never overheats and runs great.
|This message has been edited by fordsel on Oct 3, 2017 4:58 PM|