What carb for my Fury's 318 Poly?

[MoPar Maniac]

The blocks are dementially the same. The LA blocks are a thinner casting and used way lighter/compact heads, hence the term light A (LA), this was to fit into smaller engine compartments (A body). The reason the lifter bores are so low on the cam is leftover from the poly, bolt a set of poly heads on a LA block and see how well the push rods line up. Pistons and cam are different as mentioned

The blocks are not the same dimensionally. If they shaved weight it was on the outside so the block is smaller. The bore/stroke and bore spacing are the same.
Poly crank wont work in late 273-360. Thats from the guys who designed them.

 

[70bigblockdodge]

So I guess these people shoving 4" LA cranks in poly engines for 390" engines are just making stuff up. Whatever switching all this stuff around is way beyond the scope of what the OP was after in the first place.

 

[70bigblockdodge]

Engines: Poly 318 "A" Engines vs. LA 318 Engines
Here is a link that might shed some light
How To Give A 318 Poly Engine More Power - Mopar Muscle Magazine
or
A series Chrysler small block V8 engines -277, 301, 303, 313, 318, and 326

A early top fuel trick was to use a poly block (more available than chasing down Hemi engines) under you first gen Hemi heads on matching deck height engines. The Poly was a way to cheapen the engine and be easier to produce than the Hemi but they did not reinvent the wheel, then the poly was made lighter and more compact (LA) to fit A bodies again not reinventing the wheel.

 

[RCB]

I'd keep your poly and rebuild it and drop the LA in while you do. They are great motors. You can put the mopar 318/340 stroker crank in it. The yahoo 318 poly list is the place to go. Gary Pavlovich is the guy on polys. The heads have loads of potential. The motors are very durable.

 

[Mr Grumpy]

Update time,
Finally got around to doing something with the Fury, some friends gave me a hand to pull the motor and box a few weeks back and the poly sat on the stand until last weekend.
It's vacation so I got stuck into it,
I can now say to anyone who is interested a '68 318 LA crank is a straight swap into a '67 318 Poly.
The Poly's #1 & 2 rod journal was in a very bad way, but fortunately no serious damage to the rods. One of the shells was virtually nonexistent and the other pretty bad, but all the others were pretty good with very little wear.
So a good clean, a full set of new shells, a good 318 LA crank, high volume oil pump, the usual gaskets etc, and it's running sweetly again.
Not too costly, except in the swearing department, there was lots of that.
I also took the opportunity of fitting new seals in both ends of the tranny and the selector shaft while it was out.

 

[Mr Grumpy]

Another update,
A friend of a friend of an acquaintance of somebody I bumped into, (you know how these things go) put me in touch with a guy who he sold a complete running 318 poly to, the guy planned to turn it into a table and wine rack.
So I did a deal and gave him all my stripped 318 LA motor with it's knackered block and the knackered Poly crank plus a few bob for his trouble, and I currently have a spare complete poly in the garage.
Now I find a couple of old fellas in the village breaking a rotted out mid 60s New Yorker, its 440 is in bits but apparently all there.
The temptation is great.

I was thinking that with a set of headers and an aluminium intake the 440 probably wouldn't weigh much more than the all cast iron Poly.
What else would I need for the swap?

She who must be obeyed will most certainly have something to say on the subject. ;-)

 

[Dads300]

You will need the complete engine with everything to make it run, including all of the accessories/brackets for the belt driven things, and a transmission with big block bell housing pattern and the kick-down linkage bracket for the intake manifold (re-use/mod your current linkage). You will possibly need a larger radiator or one with the inlet/outlets in the right places depending on what is currently in your car, and you will need to mod your exhaust system to connect. That's it in a nutshell.
Travis..