Liger

I am planning to do an engine swap in my 1986 IROC-Z from a 305 TPI to a 454. I am wondering if anyone can give me any advice that can help me to perform this swap better? Some things I might need to know? or where I could get a 454 for less than $800 that at least ran when it was pulled? Thank You!

Rice Killer87

it can be done,but with work (famous last words on an F-body)

headers are a problem,and theres things on the car that need to be "clearanced" for them to fit from what ive heard.

a big block in a third gen causes alot of problems w/ overheating b/c of the crappy stock cooling system and small engine bay...with a BBC in there its going to be ALOT worse.

youll need to put a big radiator in there,and not sure about fans b/c a big block will come farther forward than a small block, and i havent rear/heard if factory dual electric fans will work and even if they fit i dont think they flow enough air.

do a search on this topic b/c it has come up several times and u might find some good links that way.

trwchevy

about teh fans....you can get the fans where you can reaverse the polarity's and make it push air so you can mount them in front of the radiator where they would push air through the motor....

greezemonkey

Hey, Pm or email me I have one and I can tell you all off the secerts, Check the link in my sig.

Stephen 87 IROC

Mine fits with no problems but then I also have a totally stripped down race car so I have no interference problems from things like heater or wiper motors. I also have a 6" cowl scoop on the car now and the new engine (see below) will need a hole cut in the cowl. I also agree that the Hooker Supercomp headers fit badly but they're also the cheapest. There are a few better headers available but at 2-3 times the cost. I also don't have to worry about an exhaust system.

This winter the engine gets another upgrade and rebuild. Here's how it looks ready to go into the car once I get finished playing around with the engine bay. Should push my into the 9's at altitude with an estimated 850 HP.

www.hardtail.com/pics/temp/engine2005.jpg

Stephen 87 IROC

As for finding an engine, you can usually buy a rebuildable core for less than $1000. Many are around $500. Don't expect to find a complete running engine for less than that unless it needs some major work. You'll need it as complete as possible because things like alternator brackets from a SBC won't work on a BBC.

Liger

Thank you guys so much for your help! Hey greezemonkey, I emailed you about the secrets and all! I would really appreciate your help since you done this already!!! Thanks so much again!!!

greezemonkey

no secerts really, but I can tell you that I hear alot of talk about the swap that just isn`t true, so if anything I can strain out the BS for ya

Liger

OK, Here are a few questions that I can think of right now:

-Any mods in the engine compartment to make the 454 fit?

-Are headers a problem? I heard you can get big block headers for third gen Camaro's, is that right?

-Will my IROC suspension system hold the extra weight?

-What Automatic trans is best for that engine? I was gonna use a Turbo 400

-If you have the right setup, will the engine fit under a 2 3/4" to 3" Cowl hood?

-What are the best ways to go about building the engine? Buy a block or complete engine?

-Key question: Can I do this on a budget? lol!

I m trying to sell a bunch of things right now cuz I am not alound to buy an engine until I sell my project bike. If I can sell it for $800 and afew more things to get me over $1000, will that be enough to get me started?

Thanks for being willing to answer my questions! I'm sorry for all the questions! Its just that I have been dealing with so many other people and they havent really helped me at all! I know a few things! lol! Thanks again!

Rice Killer87

as stephen 87 said,Hooker makes Super Comp headers for a BBC in a 3rd gen but they are the cheapest and crappiest fit from what ive heard.

i dont know much else about a BB in a 3rd gen besides what i mentioned in my first post,so ill let the guys that KNOW for a fact post the other stuff.

good luck!

Liger

Thank,I may have to go with them cuz Im on a budget! Thanx for your help!

greezemonkey

The only mods to the engine bay I can think of was the A/C Heater box, there was one screw pearch that had to be trimmed down so the lower rear corner of the valve cover would clear. The rear control arm pearches are Very close to the hooker swap headers, clearence that arm pearch if you use those headers or get a tubular k-member. I did move the brake lines from the master/combo valve area so that they ran between the column shaft andd the frame..stock route is on the engine side of the column shaft.

The headers are a problem, a big problem..avoid the headers if u can they will create days of fabbing and welding that is just not enjoyable. A member on TGO ...(496chev) used avalanche 8100 tubular manifolds and they appear to be a good fit from pictures I`ve seen.

The suspension will need a lot of help...if it`s old and cashed out you`d better get new springs and make sure all of the links and ball joints are in good shape, going to a iron headed BBC will add about 250 pounds..this will make your already underbraked iroc even worse..This is something you should consider even if you never upgrade to a BBC, get some bigger rotors and calipers on that car.

Which automatic trans is best for the engine..a new one or a rebuilt one, the Th400 would be a good choice but it cost less to leave the 700 in there, you`ll have to deal with torque arms and crossmembers if you change to the three speed..either way it`ll cost...I`d leave what you have in there for now and get the engine and hope it holds till you can upgrade that.

the short deck BBC will fit under a three inch crowl, with a victor jr or rpm with a holley as long as you use a drop base air cleaner..I`m running a 4 inch k&n with a three inch crowl hood right now

Best way to get a BBC is to buy one used that you can hear and see run..have someone that knows engines well check it for you, if you find one that way. Building your own will be $$$ all kidding aside My first build up ran 5,000 for the long block with acc`s mostly stock stuff too. That 450 HP 454 crate from GM is a good deal at around 4 grand,.. rect port heads, roller cam, steel crank, forged pistons, 7/16 dimple rods...it`s all the good stuff. After a while a solid roller and some other add on`s will get you 550hp in a hurry

Can you do this on a budget? yep,.... a big budget

Stephen 87 IROC

If all you want is a BBC under the hood then yes it can be done on a budget but there won't be much more performance than a SBC.

You can drop in a totally stock BBC yanked from a pickup truck. Motor mounts and V8 tranny will bolt right up. Use factory cast iron manifolds with no clearance problems. If you use the factory intake manifold then the extra weight will be about 200 pounds more than a similar SBC. Swapping to an aluminum intake will put the weight closer to 150 pounds more than a SBC. Think of it as having to carry a passenger around with you everywhere but you have the extra torque from the BBC to compensate for the extra weight.

Go with a TH400. Although the 700R4 will work, it won't survive. The downside is that the TH400 is big and heavy plus it eats up about 44 hp. A properly built TH350 would be better for most people. The 700R4 to TH350 is a simple swap.

As mentioned above, a good BBC should cost around $5000 depending on what parts are in it. I can't see just getting all the proper machine work for less than $1000 unless it's a dirt cheap, throw it together, rebuild.

Liger

My main concern is just getting a running 454 under my hood! It dont have to be the hottest thing around here but I at least want it to have some power to it! Would you get a 2-bolt or a 4-bolt? I keep hearing it should be a 4-bolt and so far thats what I plan on getting! I heard that turbo 400s are the best! Is the turbo 350 less of a trans? Once I get the engine built I plan to sell both the 305 and 700r4, and with that money buy the new trans. Are all headers the same or something, dealing with the 454? The cant all be a problem can they? Its just if I am gonna have a BBC hen its gotta have headers! Thats how I feel anyway. So what is the biggest lift cam you would go on a 454? I want it to really rumble! THANKS!!!

Liger

Yeah, maybe it may be cheaper for some people to get a small block stroker, but I want a big block! I dont care about anything other than the fact of having a big block under my hood! Would block hugger headers be the best? Thanks!