Transmission questions

[Zachary Hendrix]

First time poster here. I'm not sure how to ask my question without going into a fair amount of detail. I have a 1994 k1500, i bought with a messed up trans and a '350 from a suburban' - note the quotation marks. I work at a dealership and our transmission guy is really good with these transmissions so I took it out and had him rebuilt it for me and he updated all the internals to the 2006+ mechanically but electronically its still a 1994. He tells me it's good for my eventual horsepower goals (600). Everything great and fine but this truck is a dog. Misfires alot has all sorts of issues with the engine, won't idle properly, Yada Yada. I decide to pull the engine. And before we take it apart we look at the casting numbers.... It's a 305... And the heads are for a 350...

I was pretty unsure of what to do, however out of the blue I have an opportunity to buy whay should be a good 1998 350 vortec with ecm and full wiring harness for a great deal. There's enough there I have several options but my favorite, if it will work is use the ecm, the new engine and harness and plug it into my 1994 transmission. The question is, can I make it work. Will it run fine? What tuning might I need to do, or transmission modifications to make this work. I'm not opposed to swapping valve bodies and/or tcc solenoids to make this work, and from what I've read that's the biggest difference besides just obd1 to obd2

[m&jtrans]

IIRC we used to put 350 heads on the 305's slot because the 350 head had better flow numbers. You shouldn't have to change anything on the tranny to make this combo work and play well together.
Have you heard the donor engine run??
Were all here to help and there's no dumb questions so ask away. The more details you can provide the better the answers...

The Blue Mule

[riverbanks]

Get the flexplate with motor,they changed,and your gonna need a proper fuel pump,tbi to spider,mucho psi difference

[riverbanks]

And your goal of"600"h.p. is not gonna happen,think about a l.s. swap