I just wanted to preface with thanking this forum for basically providing me with a wealth of Cadillac HT engine information that nobody else on the internet could provide. The most popular Cadillac forum on the internet couldn't even really provide any solid information for anything. The Fiero guys truly are the mad scientists of the automotive hobby, and I can't thank them enough.
So here's what I have and here's the rough plan I have.
I own a 1988 Cadillac Eldorado with the original TBI 4.5 V8 and 4T60 transmission. Both unopened to by knowledge. I've mostly stuck to custom suspension and exhaust upgrades with this.
I was heavily considering a full LS4 swap, but as you can imagine, "bottom dollar" quickly gets thrown out of the window when you add up the transmission building costs, fuel system, cooling system, exhaust system, and ECU. I have bills to pay, and student loans sucking the life out of me.
A 4.9 swap is about as close to drop-in as I can get with almost zero modifications.
However, I want to do a 4.9 swap WITH the Allante Intake (Why make life easy?), and I could use this forums help for a rough guestimate of what "gotchas" I might need to address. I have read the fuel system runs at a higher pressure for the MPFI Allante variant, so I'm assuming the bare minimum I would need to perhaps swap an Allante fuel pump into my Eldorado's tank.
Mounts would all be the same, and theoretically, even the exhaust should just bolt in without an issue.
Now I do see a thread about swapping the intake, but it seems like you all were talking about tuning it, but I don't see much on the ECU used or any intake mounting concerns.
https://www.fiero.nl/forum/Forum2/HTML/146204.htmlThat's kind of where my questions start. If I want a 4.9 with the Allante style MFI intake, I need to block off the EGR and I see at least have it tuned to run with the EGR off and increased air flow. Do you guys just use a modified 4.9 ECU or an Allante 4.1 ECU?
I've really only messed with my carbed smallblock on my C10, so I'm honestly not even sure how to push any sort of "tunes" to a pre OBD system anyway. Er, I'm assuming my these would be pre OBD1. Do I need to burn a PROM chip for it?
Additionally, since I'll have the engine out and have to take things apart anyway, are there any recommended cams for the 4.9 I can order? Additionally are there any preventative maintenance things I should do? I'm assuming a water pump, head gaskets, or at the very least valve cover gaskets?
I'm shooting for like a 2k job if I do everything myself. Obviously an optimistic estimate at best.
I'm hoping that this topic can be a good reference point for anyone else in the future attempting a 4.9 swap into a Cadillac of the same era. If the Caddy forums can't help, at least this one can.
The Eldorado: