Hey guys. I've been considering upgrading the 350 ('78) to a 454 (Mk IV)recently, and have two questions for you. I searched, but didn't find a clear answer on either. A) I have the Super T10 setup from an '82 in my Camaro, with scattershield and hydraulics from a later 3rdgen. I know the bellhousing will bolt up, and from what I've read, the flywheel *should* bolt up (its for a 2pc rear seal sbc). So question is - will the flywheel bolt up to the 454? All I should have to do is have the flywheel rebalanced to 454 specs, correct? B) Will the stock BBC exhaust manifolds work in a 3rdgen chassis? I know I'd have to have a custom Y-pipe made for the big block, but will the stock iron manifolds work in a 3rdgen, or will I have issues with the firewall, steering gear, frame, etc? Oh, and whats the hood clearance like with a generic cast iron 4bbl big block intake? I'd just put my nice running Qjet on it for now, with the L88 air cleaner I got when that gets here. The 454 is just a stock 'service replacement' engine that was run on propane since it was put in the truck it just came out of - so its EXTREMELY clean internally. Not even any carbon in the exhaust manifolds. I like this motor because it is a 4-bolt block, but more importantly, its so clean inside, has almost no mileage, and has the good large oval port heads, which I hear make an excellent street/strip head (781 or 761 casting, I can't remember which now). Its a weak-knee'd 240hp engine IIRC, but would make a nice base to build on later.

You cannot use the small-block flywheel on a 454. Also, all 454s were externally balanced. That T-10 is the weakest T-10, rated for 285 ft-lbs, while the strongest, the one with the 2.43:1 first gear, is only rated for 375 ft-lbs. Your easiest uption would be a Richmond 4+1. As for the truck exhaust manifolds, I've tried them, conventional, upside down, swapped side for side, swapped and upside down. They cannot be used. Period.

Do like me, T56 in the back of that big block 6SPEED!

The 454 is an externally balanced engine and uses a specific flywheel/flexplate. It's balanced differently than a 400 SBC so you need a flywheel/flexplate specifically for the 454.

You could buy an aftermarket internally balanced crank and have the engine rebuilt so that it's internally balanced. Then you could use the 350's neutrally balanced flywheel/flexplate.

As for manifolds, truck manifolds normally will not fit. You would need to find some car manifolds from something like a Chevelle or early F-body that exit closer to the rear. Chances are, they'll cost more than aftermarket headers.

The 781 casting heads are very good to use. Some port and polish work and have them upgraded to 2.19/1.88 valves will really wake up the engine.

Ditch the cast intake. It belongs on a truck. Any dual plane aluminum intake is worth the investment. Some may come with a single bolt pattern, other may be available to use a spread or square bore carb.

So the small block flywheel can't be rebalanced to work with the 454?

I'm just looking at what it would take to get it in and running as cheaply/quickly as possible (I know, its a contradiction with a BBC) and do the upgrading later.

Reason I'm thinking about this, is that a friend of mine is interested in the 350 thats in the car now as a backup for his Trans Am, and another friend of mine has this 454/TH350 for sale. Seems like a good time to swap if any time.

I'm not opposed to using the TH350, just would like to keep the 4-spd if its reasonable to do so. The driveshaft I use with the ST10 should work with the TH350. Not sure about the crossmember tho.

It would probably be cheaper to buy a BBC flywheel than having a machine shop balance a SBC flywheel to work with a BBC if it's even possible.

The Super T10 will have the larger output shaft, the same size as a TH400. The smaller output shaft is used on T5, 700R4, TH350 etc transmissions. To use the TH350 tranny, you'll have to change the slip yoke on the driveshaft and maybe the driveshaft length. Depends if the TH350 is a long or short tailshaft.

They make a counter balance for a 454 that bolts behind the neutral flywheel, i forgot about that.

They work perfectly.They sandwich between your flywheel and the end of the crankshaft,and will allow the use of your current flywheel.I think I have one laying in the shop somewhere,PM me if interested.

As far as hood clearance,the stock intake sucks,but I think it along with the Q-jet would fit under a stock hood.I'm unsure on the exhaust manifolds,but surely there is a combination that will work.Unfortunately BB exhaust manifolds,as previously stated are pretty pricey,even used.
I've had 1 BB 3rd gen,and am building another one.My words of wisdom are,don't be talked out of it,unless you are big into pulling Gs roadracing.It is one of the most fun combinations I've ever driven,and the "poor handling" that you always hear about,is minimal if at all.

I do want to do it, but I just want find out the quickest reasonable way to get it in and running. Upgrades, like the intake, exhaust, etc.. can all be done afterwards. I'm in no big hurry there.

I, too, forgot about that balance plate thing.

Afterome searching and looking at past threads here, there seems to be actually two different truck exhaust manifolds, and it looks like one of them may work.

This is the early '70s design:



These are the late '70s and up design:



It looks to me like the early '70s set may work in a 3rdgen chassis, which is what I believe this engine has on it.

I wonder if the truck pan will fit into a 3rdgen chassis, or if the Chevelle pan is req'd?

I was using '94 Suburban exhaust manifolds and oil pan. Also, I was using Moroso 62510 and 62610 solid mounts. The oil pan was just touching the crossmember, a little hammer work gave me 1/4" of clearance.

Ok, so with a little persuasion with a hammer I should be able to use the truck pan then. Thats good to know.

Also, I just checked the specs for my Lakewood scattershield and appearantly it will fit both a 153 and 168 tooth flywheel, so thats somewhat of a victory as well I guess. So I could either go with the balance plate behind my existing flywheel, or get an external balanced 168 tooth flywheel and matching starter.

Now the only issue I have it the exhaust manifolds. You say you used the later style manifolds? Did they work in the car as-is, or did the hammer have to come out again? Pics would be awesome if its possible...?

It will take a fair bit of hammering to get a truck pan in there.The Chevelle style pan fits perfectly,with no hammering needed.
Another option on exhaust maifolds,or so I'm told,are the later 99 up 8.1 liter manifolds.I don't know that they would work for sure,but I'm pretty sure someone on here used them at one time or another

I never got the manifolds anywhere near fitting. I tried them as intended, then upside down, then swapped side to side for front dump, then swapped side to side and upside down. All 4 ideas were failures. The '94 Suburban exhaust manifolds flat out will not go without extensive butchery, and I wasn't willing to try any butchery. I hope this info helps.

Another thought I had today... these look like an easy solution for a relatively cheap exhaust. I can make my own Y-pipe, so thats not an issue. These look like they would work fairly well in a 3rdgen chassis, and at $150ea for reproduction parts, they aren't overly expensive. I hear they breathe reasonably well too (they are repro '66-69 427 Corvette parts).

Thoughts?

My first thought is that driver's side one seems likely to hit the stock crossmember, but might clear an aftermarket tubular K.

That's more the log style factory manifold I was thinking of. They're also big and heavy and usually cracked.

Another option is to buy a set of block hugger headers. Here's a set with large enough primary tubes so they're not so restrictive.

http://www.jegs.com/i/Hedman/500/68510/10002/-1

I saw those headers too - but would those clear the crossmember?

Edelbrock 65193 look like a possibility...? Not cheap though at $460. They are meant for an '03-06 8.1L BBC. Coated and made of stainless though.

If you're going to pay that price, you might as well just buy the Hooker Supercomps designed for a third gen. The stainless headers will last the life of the car. I have stainless headers like that on my daily driver truck. They were installed back in the early 90's and although they've turned brown like all stainless headers will do, they're still in good condition. With no iron in the metal, the don't rust out like the cheap mild steel headers will do.

If those look to fit,why not call a local salvage yard and see what a set of stockers go for?I'm thinking you'll end up with long tubes down the road as you upgrade,no need in tieing up too much now,at least in my opinion.
Unless your dead set against the Hookers,There is a set on Holley/Hooker's ebay store right now.They are scratch and dent headers,but are ceramic coated,and if I remember correctly,are at just a little over $400 buy it now.I'd have already bought them,but I'm still installing my cage,building a 9",etc.Need the money for other stuff at the moment.
The Hookers are a bitch to get in,but I had good luck with my last set once I got them in.

I'm not set against the Hookers, but it sounds like theres alot of cutting and bashing req'd on the car itself to make them work. While I'm perfectly capable of doing that stuff properly, I don't really want to if I dont have to.

This swap, at least for the time being, is not for a full-on race car. I'm just looking for a nice cruising car that I can just get into and drive, whithout having the same stuff that everyone else has (ie. SBC or LSx).

I just stumbled on this by accident, but I found this set of headers on a website mainly dealing with old-style hotrods, but what got me interested, is that they list it as "used with 67-92 Camaro clip"

For $325 they cost less than the Hooker swap headers, and look like alot less hassle to deal with as well. Same tube and collector size as the Hookers.

What do you guys think?

Here's the page that lists them as '67-92 Camaro BBC'
http://www.chevsofthe40s.com/detail/13285.html

Here is the 'Sanderson Headers' page listing them (they are the mfg). They say simply "fits all year Camaros"
http://www.sandersonheaders.com/prod...products_id=32

passenger side looks a little iffy to me,like it might interfere with the firewall.If you could try them and return them if they didn't work,it would be worth a shot.

65193 Edelbrocks look good for a mild cam, if you're willing to hammer on the firewall in the area of the passenger footwell.

I used stock motor mounts and dorman part # 674-159, and 674-161. These are stock passenger car replacements. I did have to take a hammer to the passenger side firewall to make room for the down pipe. It was not an excessive ammount of pounding, just two inches or so.

I don't think there are any exhaust options for a BBC in a third gen that will fit with out some kind of cutting/ hammering.

The stock low profile castiron manifold with a Quadrajet and a low profile aircleaner will clear the hood with stock motor mounts. I put an edelbrock performer 2.0 part #2101 with an edelbrock air cleaner and stock Qjet. It will not clear the hood.