vivalabouch

I have just bought a 1985 trans am it has a 305 and a 700r4 trans.
I have a 454 not being used and I would like to swap this in but half the people on line say its not possible the other half says it is.


Is there a kit I need?
will the stock motor mounts work?
and has anyone done this?


thanks

357 Camaro

It's been and can be done. Look up in the important stickies says BBC swap all the info needed. Goodluck

AlkyIROC

Basically it's a drop in swap but there are always going to be some issues.

The biggest challenge is the exhaust system since there are very few if any cast manifolds which will work. Swap headers are not cheap.

Clearance issues with heater box and wiper motor will depend on valve cover choices etc.

The engine is longer that a SBC. That's why it's called a big block. It has wider bore spacing. SBC and BBC share the same bellhousing bolt pattern but a 454 is externally balanced so the proper flywheel/flexplate needs to be used. If your transmission is using a 153 tooth flexplate, chances are the required 168 tooth flexplate for the 454 won't fit inside the bellhousing without some modification. The position of the engine mounts is in the same location so the extra length of the engine moves forward. This may cause clearance issues with the rad depending on what water pump/fan system you use.

No engine swap is impossible. It just depends on how much time, money and fabrication skills you have. The cost of the engine is the cheapest part of the swap. Calculate how much it will cost to do the swap then double it. That should get you close to what it will cost when finished.

Don't forget that it's also a package deal. Dropping in a BBC which produces more torque than anything else GM put into these cars means the rest of the powertrain will need upgrading as well. You can run the factory driveline for a while but it will eventually break and will need to be replaced with something stronger.

PAFORM350

I have an old hot rod or car craft magazine which shows a 455 swap into a 1987 trans am if I remember correctly. Not the same engine but I bet it will interesting for you. I'll see if I can find it

vivalabouch

very helpful guys . I have done engine swaps before but just wanted to know how extensive this one was. I think I will do this and will post pictures along the way. wish me luck and any info along the way will help . \Thanks again

slade5612

I have included some pics for you. The biggest issue I had was the headers, the brake booster and the power steering. Oh and the wiper motor absolutely did not fit at all. So I relocated the alternator and power steering and got the smaller booster. I found a guy who sells brackets just for doing relocations. The deal was get the relocation bracket and then buy a power steering pump for an 85 Pontiac sunbird. It has a remote reservoir. Than I found a cool looking reservoir I think from a Lincoln navigator







Your in luck

I just finished my car and joined the forum today.

I have a big block (stroked 496) putting out a little over 800hp to the wheels and have been through that exact project only I stuck with a turbo 400 manual valve body for racing. And fun on the street. :-)

There is a set of direct drop in headers for this project. Well I would call it a direct drop in. However it is not what you think. It is a part number for a mid 70's Chevelle. They just fall right into place. I actually found the part number on this forum while doing the build they were patriot headers I believe. The headers they say work for this project are no where near close to fitting without major work. As the project took me several years and I just got it back from paint yesterday I would have to dig up the invoices but I have them all in a box.

tealrs

i used the patriot headers 8012's i think the 1-3/4" primarys. stock style gen v valve covers with a half inch spacer fits under wiper motor no prob. i dont have a heater core in it its been blocked off by sheetmetal and thats where i mounted my ignition box. exhaust is a trick all custom work. i use a dodge intrepid dual electric fan setup i have to run on low and high or it gets warm. 3" core radiator. a shorter oil filter wix 57099. i built a mid mount serpetene belt system. and i use the 72 pancake lo-profile intake manifold. 550hp
plan on a differant trans th400 and s60 or 9" rear axle. the stock motor mounts are fine, bolting in the block is the easy part.

AlkyIROC

I look at those 1-3/4" headers and they look so tiny. They're a good street header for a basic 454-468ish engine. For high HP, high rpm, a minimum of 2" should be used. Why make a high HP engine then choke it off with small headers?

My 588 has 2-1/4" primary tubes and 4" collectors. They really fill up the area between the engine and the frame rails. Mine are early Ed Quay headers. I'd love to have some late design ones. The #8 tube right now loops around on the top. The later design has the loop under the car. I can't remove my starter without removing the header. One tube goes directly under the starter bolt.