well first off I hope you are aware that swapping in a stock unmodified 429 will just make the car slower.
the 429 is not much different than any other engine swap when you know you have to fab mounts and modify things to make it work, it should be pretty straight forward
one thing to note, if the engine hasn't been gone through then there's that. Just expect to have to go through the engine before tossing it in.
the stock marauder ecu can run that engine perfectly fine, if you have any issues just LMK I can get you squared away with no problem I've run several big blocks on the stock ecu's over the years
you will need to fabricate a 35 tooth reluctor to the front of the engine same as the stock marauder engine uses, you will have to sacrifice a distributor and fab up a single tang with a VR cam sensor but thats no big deal.
Take the stock coil on plugs from the marauder engine and rip the boots off. Get a set of ls1 plug wires and you can clip them on to the stock CoPs which will give you coil near plug. If you want to get fancy you can take an ls3 coil bracket that mounts to the valve covers and make that work or just make one. Or just secure them out of the way.
You will have to drill injector bungs in the intake and make a fuel rail fit. I usually use the edelbrock fuel rails since they are nice and cheap and just drill bosses in the manifold and weld in a bung to secure the injectors. You'll have to make a mount for the rails which is as simple as modifying the edelbrock mounts or use an L bracket. You will need a ford FRPS adapter to re-use the stock FRP sensor. The stock marauder fuel injectors will work perfectly fine.
Rip the carb off and toss an edelbrock 4150 adapter elbow on it. You can get the ultra low profile elbow and use a 3/4" spacer to give you more clearance to help clear the hood. The stock marauder maf will work fine no problem.
Prob should factor in a raised hood or modified hood at the least though.
you will prob have some issues with the exhaust manifolds. Your only option may be to flip the forward and route them down and around to mate back up with the exhaust.
For the accessories you will most likely have to redrill and modify the original bracketry and most like fab up some mounts. Should be pretty straight forward.
The ac lines are going to have to get redone. Any competent hose shop can fab you up some new ones.
most likely your going to run in to some issues with wire length and maybe some wiring harnesses on the driver side may get in the way. Factor in having to extend some wiring and moving others.
The stock fan and shroud is probably going to give you some issues with clearance. I swapped a 2018 mustang fan on my marauder to gain additional clearance. Just to need to make some mounts for the fan which is nothing special.
The stock marauder trans can handle anything that engine can produce with no problem I've put much more through them than what that engine will make. The bellhousing is not the same though on the modular as the big block. Its a bit involved to swap the bellhousing but it can be done if you have a competent machine shop that can cut the case and align a swap bell-housing to it. You will have to tear the trans down to cut the case and weld up new replace-able bell-housing attachments.
https://www.cjponyparts.com/perform...ng-sfi-pro-fit-big-block-aode-4r70w/p/BELL19/
