You gunna ponny up $5000 to $6000 for the motor and driveline for the fellow? That'* about the going rate on a used LS4. A late-model Northstar is about $2500 to $3000 with transaxle, accessories, and wiring. Less, if you go back further in age. When you get all the way back to the Allante/Seville/etc you are down to about $1000.

Here'* an interesting one, ebay item 320041478248, a 2004 Northstar complete for $3300 in Michigan.

And at the other end of the spectrum..110054099100 a 94 Northstar currently at $49 with no reserve. (looks like it'* complete and sitting on a subframe...heck, if it goes under $100, it might be worth the shipping from Missouri or a drive to go get it.)

I've always like engines that are made out of iron and have pushrods. The Northstar, although powerfull, is not very strong. The block is made out of some kind of strange ceramic aluminum mix, and the head bolts always rip out of the block threads. Then you have the issue with the connecting rods: powdered aluminum. For my money, it would be a built up L67 with over 400HP without nitrous.

On that note, why don't your and find a 66 Toronado with a 425 cubic inch engine and turbo 400 trans and see if it will fit. The Toronados were front wheel drive and puts a good 345hp with over 400lbs of torque, if that doesnt work try and Eldorado with a front Wheel drive unit. I remember when I was in high school and I had a rare 1975 Pontiac GT Astre and put a LT-1 350 from a 69 corvette and turbo 400 from a 1970 SS Chevelle and all my friends told me I couldn't do it. So another friend decided to put a 351 Cleveland in his pinto and we dragged and dragged and dragged, I would get him every time due to mine was an automatic and he had problems keeping his back wheels from spinning out due to his top loader 4 speed. Damn I miss that GT Astre just think of what the imports would think bout that!

An Eldo? With the 505 c.i. V8

Too bad it was watered down a lot due to emissions, but I'm certain you could wake it up

a 505!?! that would be insane, and im sure a little bit of a challenge to fit in there as well...

I haven't seen under the hood of a '76 Eldo, but it HAS to be BIG

Here is the monster....

but that isnt front wheel drive though

Actually, the Toronado is a FWD car, it just doesn't have the motor in a transverse orientation. Like Ferarri, the motor is longitudinal with a transmission (TH425) case under it.

From a practical standpoint, it, and the older caddy FWD motors are physically too big to stuff into the Bonneville engine bay. You would have to remove everything in front of the firewall and construct the front end yourself. So, in the context of your swap ideas, it'* a rediculous proposition.