Ford Muscle Cars Tech Forum banner

1 - 10 of 10 Posts

·
Premium Member
Joined
·
2,806 Posts
4.5" stroke crank with .030 over gives 545 and I know a 4.75" stroke crank will fit in the stock block for a 575 and with an .080 overbore and 4.75 stroke is a 588. .120" over 4.48" bore with 4.75 stroke is a 599. Many '68-'71 block can go .120" over and some can go .150" over but you really have to get a good block to go that far. Sonic testing is the only way to find out but .080" over is safe without sonic testing for any 429/460 block thru the late '70s. Blocks newer than the late '70s I don't know anything about.
 

·
Premium Member
Joined
·
2,806 Posts
Oh, a 6.65" rod for the 4.75" stroke and a 6.7-6.8" rod for the 4.5" stroke crank. The 4.5 stroke crank is cheap and is a cast crank. The 4.75" and 4.85" stroke cranks for stock blocks are billet(very costly).
 

·
Premium Member
Joined
·
14,758 Posts
A 4.750? Got a Callies that won't fir in the 4 I have. Now you know why I bought them. Called them Monday & was told 4.500 was pushing it in any 385 series production block. Engine Systems says 557 is the absolute max for a production block.
 

·
Premium Member
Joined
·
2,806 Posts
The bottoms of the cylinders on older short cylinder blocks need to be notched for rod clearance with 4.75 stroke but still fits. Those are expensive cranks though and I don't know if the later long cylinder blocks will work but they might. 4.5" stroke drops in with no clearance issues at all and no clearancing needed at bottom of cylinders on the earlier short cylinder blocks.
 

·
Registered
Joined
·
242 Posts
Who carries the 4.5 stroke crank, and were can you get the rods?
 

·
Registered
Joined
·
127 Posts
I used a scat billet 4.5 stroke crank. The problem is the waiting for them to make one. They say 12 weeks but always ends up longer.

The rods can be bought at any performance shop. The brand and style of rod all depends on the application. For example if this is a 600 horse power deal, something like a eagle H beam rod is fine. For a crazier engine you might want a billet rod.


Your machine shop that will be doing your motor should be able to help you out with part selection.

Good luck
 

·
Registered
Joined
·
82 Posts
I just bought a 545 stroker kit from Scat. It looks beautiful. It's 4.5 stroke, 6.7 rods and 4.390 JE 13:1 piston. I figure at .030 the bores are ultra stout and there's plenty of room for the future. Price was $1871.00.
My machinist is checking clearances now, but I anticipate no big job to put it in my '73 lincoln block.
 

·
Registered
Joined
·
749 Posts
Has anyone tried that 4.14 cast steel crank from Eagle that jegs sells for 399.99?
KB shows a hyper piston(KB152) for a 6.8 rod and for that stroke that gives 10.7-1 with 76cc heads. Summit sells them for 357.39.
Flatlander racing has a 6.8 H beam rod for 359.00. To bad there isnt a cheap 6.8 I beam rod out there....or is there?
 
1 - 10 of 10 Posts
Top