1981 Arrow 2.6 need an engine

[phish1270]

Guys,

I bought back a 1981 Plymouth Arrow last year that I had previously owned. It had a bad head gasket. My son & I pulled the motor & trans to have everything rebuilt. I had professional shops do both. The motor was completely rebuilt & we bought a brand new head for it. Well, my son has been driving it for around 7 months, around 5k miles & I'm 95% sure it has a bad head gasket again. It is messing up #4 spark plug with white deposits, radiator continues to bubble even after 20 mins of running & the radiator builds pressure fast as soon as we start the truck. I can't put anymore money into this motor, it is cursed. This is the 3rd head gasket that I know about.
My question is what motor would bolt up to my transmission? It is an automatic. If I need to get numbers off of it I can. I am weighing my options between selling it, finding just a motor that bolts to trans or looking for an entire drivetrain to replace motor & trans. Swapping in a motor that bolts to existing trans seems like the easiest & most affordable. I've heard a 4G63 will work but not sure where to find one. Any help is greatly appreciated. Thanks

[tortron]

the head has probably gone soft
when you pull the nuts off the studs are the washers sunken into the head? they lose their temper and become too plastic to seal any more. you can get new complete heads for pretty cheap

[phish1270]

the head has probably gone soft
when you pull the nuts off the studs are the washers sunken into the head? they lose their temper and become too plastic to seal any more. you can get new complete heads for pretty cheap

It is a brand new head, barely has 5k miles on it. I had the motor built by a local Mopar shop & I personally retorqued the head bolts at 500 miles.

[dash]

Our resident machinist on starion 2.6 forum said an unusual amount of 2.6 decks he found were not flat

4g63 twincam motor is from eclipse family. Conversion details on this site. Not straight foward at all
Your automatic(& early) 2.6 most likely a narrow block, same as the 4g63 dohc, so will bolt up..... then gets 'fussy'

Complete starion 2.6 if you wanna make a project of it. Can still find donors, but not dirt cheap like they used to be

Automatic starion 2.6 are wideblock, as are later motors
You'd have to modify fuel delivery system. Ecu/wiring not bad at all. Done many times
This guy below retained his truck block, while starion everything else. Block & auto "should" survive mild mods
Truck will be on another performance level

https://needthatcar.com/2012/01/21/project-turbo-arrow-ntcs-build-thread/

[tortron]

yeah got to be the block is not flat, it happens, disappointing that the builder didnt pick it up

probably more time effective to put a known good engine in, unless you have time to strip the block and then rebuild it. You might get away with some pour in headgasket repair in this case

[phish1270]

Thanks guys. We might just park it for now & find a motor/trans combo to swap in.