Well the head gasket finally went on my 2003 Deville. I want to keep the car but there's no way I want another Northstar. What are my choices? I'm told an LS4 could be a direct bolt in replacement but what about an old fashioned 350? Guys mount 350s transverse in Pontiac Fieros. How could you do it in a Deville? Thanks.

 

To swap anything but another northstar is going to be expensive, Cadillacs have alot intregration of systems. Old Fieros have no intregration of systems so it is much simpler. Swapping Chevy V8 in is possible but will require alot of money and time to try to make it work, some functions never operate correctly however.

 

What kind of integration problems? Why can't I just run things like a mechanical speedometer? As far as expense anything is going to be cheaper than purchasing a new car and I have no use for a Northstar.

 

Changing from a N* to any other engine set-up will cost more in the end than another car. The trans will NOT bolt up to a Chevy engine, regardless of what someone else said. Mounts, accessories, cooling systems, exhaust...pretty much everything would have to be changed/modified.
ALL of the electronics for the vehicle are in one way or another integrated with the PCM. It would be a logistical nightmare to engineer a set-up that would work, not only the mechanicals, but the electronics as well.
By the time you bought all of the stuff you would need, modified it all, installed it, and got it all working correctly, you'd prolly have $10,000 or more in it. Stuff adds up quick on projects like this.
Just not worth it, imho.
I'd have to start looking for another car, myself, but...that's just me.

 

I ordered a transverse mount LS4 this morning. There's no way I'm going to take a car I paid $43,000 for and turn it around for another $43,000 money pit. $10k is more reasonable and nowhere near as a new Cadillac. This should be fun.

 

if i understand this correctly, you have had this car since new.
can you let us know what the ACTUAL coolant change/flush schedule was on your car?



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Reman Northstar costs roughly 10k and has a warranty, LS4 will likely have none (mis-application) be sure before you drop the cash.

 

I change the coolant in all of my cars once a year.

 

If you bought car new, and had a more than just warranty repairs relationship with your dealer. Request assistance from Cadillac. You wont get a free repair, but you could get a deductible even if its 50/50 it will be conciderible less than the LS4. Goodwill out of warranty repairs are done a warranty rates which is lower than retail. If you have poor or no relationship with dealer you may not get help, but you could contact Cadillac Customer Assist. and appeal. If you are a DIY guy, you will need maint records and parts recipts to show you have taken care of car. At this point you have nothing to lose, the worst they say is no, and you can pursue the LS4 swap which I don't recommend to attempt. Your end of a 50/50 head gasket replacement 2200-2500, provided engine doesn't need be replaced due failed bolt holes. then it will be closer to 5-5.5k.

 

Good Luck with the swap.
I can't see how it's gonna work, myself. I don't think the LS4 will bolt up to the 4T80E trans....

Here's a swap on a LS4/4T65E into a Fiero...