318/904 and 360/727 mix & match

[grouseman]

Okay, this is what happens when I daydream. 

Presently I have a 1980 Cordoba/300 LS.  It has the original 318 short block, but milled and ported 360 heads and 4bbl, a 2.77 gear 904 and the original mechanical lock-up converter.  (3.23's in an 8-3/4 as well).  Got it?  Next . . .

I have a line in the water which may hook a '72 Polara wagon with a 2 bbl 360 and (I'm assuming ) a 727 trans.  It's my understanding that it is a roadworthy, albeit unpretty, vehicle.  So I wouldn't just junk the wagon after removing it's organs. 

Soooooooo

I now want to mix and match some parts here.  I'll take the 360 short block, put in the 340 cam lying in the basement, add the worked and milled 360 heads and 4bbl intake from the Cordoba to make a nice strong streetable engine for the Cordoba. 

I'll then take the Cordoba's 318 short block and put the original 318 heads on, and put the 360 2bbl intake onto that.  So it keeps the 2bbl air cleaner and 2 bbl kickdown linkage.  This will then be a completely stock 1980 318 (reasonable miles, well cared for) but with 360 2 bbl induction.  This will go into the wagon as a torquey but economical engine.  It'll also mean I have a set of 360 heads which I could sell. 

Now what to do about the transmissions?  I know the 360 will need to be externally balanced with either it's original 727 converter, or an aftermarket flex plate or weld a weight onto another converter.  Would these two converters interchange on the 904/727, or does the lockup 904 converter have to stay with it's transmission?  The 2.77 first-gear 904 in the Cordoba is nice to have as it makes the 3.23's launch like a 3.65, but I'm guessing the 360 converter may have a higher stall?  What are the dimensional differences between the two transmissions?  Here's where I'm struggling with what to do.  Is it easier overall to leave the transmissions where they are, and just get the flex plate to balance the 360/904 in the Cordoba (and unbalance the 360 converter behind the 318 in the wagon?) 

Any thoughts would be appreciated. 

grouseman
(used to be Mopartom)

[RD]

Okay, this is what happens when I daydream.  

Presently I have a 1980 Cordoba/300 LS.   It has the original 318 short block, but milled and ported 360 heads and 4bbl, a 2.77 gear 904 and the original mechanical lock-up converter.   (3.23's in an 8-3/4 as well).   Got it?   Next . . .

I have a line in the water which may hook a '72 Polara wagon with a 2 bbl 360 and (I'm assuming ) a 727 trans.   It's my understanding that it is a roadworthy, albeit unpretty, vehicle.   So I wouldn't just junk the wagon after removing it's organs.  

Soooooooo

I now want to mix and match some parts here.   I'll take the 360 short block, put in the 340 cam lying in the basement, add the worked and milled 360 heads and 4bbl intake from the Cordoba to make a nice strong streetable engine for the Cordoba.  

I'll then take the Cordoba's 318 short block and put the original 318 heads on, and put the 360 2bbl intake onto that.   So it keeps the 2bbl air cleaner and 2 bbl kickdown linkage.   This will then be a completely stock 1980 318 (reasonable miles, well cared for) but with 360 2 bbl induction.   This will go into the wagon as a torquey but economical engine.   It'll also mean I have a set of 360 heads which I could sell.

that 360 2bbl intake has larger ports than your 318 heads.  It will run not well at all.

Now what to do about the transmissions?   I know the 360 will need to be externally balanced with either it's original 727 converter, or an aftermarket flex plate or weld a weight onto another converter.   Would these two converters interchange on the 904/727, or does the lockup 904 converter have to stay with it's transmission?   The 2.77 first-gear 904 in the Cordoba is nice to have as it makes the 3.23's launch like a 3.65, but I'm guessing the 360 converter may have a higher stall?   What are the dimensional differences between the two transmissions?   Here's where I'm struggling with what to do.   Is it easier overall to leave the transmissions where they are, and just get the flex plate to balance the 360/904 in the Cordoba (and unbalance the 360 converter behind the 318 in the wagon?)  

Any thoughts would be appreciated.  

grouseman
(used to be Mopartom)

converters wont interchange due to lock up and non lock up types, and the 904 input shaft is different sized than the 727's.  The stall rating on each is up in the air, but I bet they are not far from one another at all.  I would swap tranny's, but that is just me.

[grouseman]

The Cordoba came with the 360 intake (4 bbl) on 318 heads, and it ran fine so I've no worries about putting the 2 bbl 360 intake on the 318 heads.  Thanks for the tips about the transmissions - didn't know about the input shaft thing.  I figured the lockup converter would likely have to stay where it was . . . and balance the 360 with the special flex plate. 

So the next question is, how to balance the 360 converter behind a 318?  Is there a balancing weight on it that can be removed, or what?

grouseman

[Chryco Psycho]

yes there is a weight that can be cut off the 360 converter

[grouseman]

Things sound not to bad so far. 

How about motor mounts?