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There are lots of little things you will need to purchase and consider. Its not exactly a remove and replace job. Some on the fly engineering will be required.
Things that come to mind when I did mine.
You will need new custom length pushrods. Thick wall, hardened and determine the length required. Adjustable pushrod helpful to do the measurement
New timing chain setup. Old one likely tired.
New harmonic balancer. Inspect the one you have. If original, likely has cracking rubber ring.
Roller cams walk in a non roller block will need some way to manage play such as a cam button. Timing cover should be reinforced or replaced with one that has been reinforced or adjustable. Have to check water pump clearance.
Probably should replace the water pump unless its been replaced recently. Might need new bolts
New spark plug wires. Routing will be different with headers vs stock exhaust. Looms and such to keep them off the headers
New head bolts.
Header bolts.
New intake bolts. Some go in the water passage in the head. I snapped one in the old head and they will likely be corroded.
Valve covers will not fit with roller rockers. Will need valve cover spacers or new valve covers with enough clearance
Pass exhaust manifold has case spacer for ac compressor bracket. You will need a spacer to mount the compressor. Your compressor reinforcement brackets will no longer work with the higher valve covers.
Header collector to exhaust pipe transition. I had original pre 75 exhaust setup. I used flex pipe to get it to a exhaust shop. Don't know what you will need for Dougs headers and Pypes exhaust,
Gaskets for heads, oil pan, timing cover, intake, exhaust manifolds, water pump. Header collector gaskets.
New Motor mounts if original or old. Will likely separate with the torque of your new motor
There are lots of little things you will need to purchase and consider. Its not exactly a remove and replace job. Some on the fly engineering will be required.
Things that come to mind when I did mine.
You will need new custom length pushrods. Thick wall, hardened and determine the length required. Adjustable pushrod helpful to do the measurement
New timing chain setup. Old one likely tired.
New harmonic balancer. Inspect the one you have. If original, likely has cracking rubber ring.
Roller cams walk in a non roller block will need some way to manage play such as a cam button. Timing cover should be reinforced or replaced with one that has been reinforced or adjustable. Have to check water pump clearance.
Probably should replace the water pump unless its been replaced recently. Might need new bolts
New spark plug wires. Routing will be different with headers vs stock exhaust. Looms and such to keep them off the headers
New head bolts.
Header bolts.
New intake bolts. Some go in the water passage in the head. I snapped one in the old head and they will likely be corroded.
Valve covers will not fit with roller rockers. Will need valve cover spacers or new valve covers with enough clearance
Pass exhaust manifold has case spacer for ac compressor bracket. You will need a spacer to mount the compressor. Your compressor reinforcement brackets will no longer work with the higher valve covers.
Header collector to exhaust pipe transition. I had original pre 75 exhaust setup. I used flex pipe to get it to a exhaust shop. Don't know what you will need for Dougs headers and Pypes exhaust,
Gaskets for heads, oil pan, timing cover, intake, exhaust manifolds, water pump. Header collector gaskets.
New Motor mounts if original or old. Will likely separate with the torque of your new motor
Good call on all of that. Great minds think alike! I have just about all of that stuff including the cam button along with a push rod measuring tool and new double roller timing chain. Good call on the valve covers and motor mounts though. That one I did not think about. What about the fuel pump will it be able to keep up with all of this? And why do I need to replace the water pump?
Yeah it will run fine!
Terrific even.
You have a great selection of great quality parts..
But there will be some tuning, etc required.
That is part of the fun right?
A lot of people like Magnaflow mufflers for their mellow sound, and much bigger growl at WOT.
I really like the mandrel bends of the 2-1/2" PYPES system.
Worth a few horses over regular dual exhaust, and worth a ton over a late C3 cat exhaust!
There are always a couple ways to make it better.
All it takes is time & money!
Old water pumps are prone to failure, weaping are inexpensive, and you will have it off anyways. Cheap insurance. I don't recollect changing the fuel pump but it will be off as well.
Yes, there will be lots of little parts big and small that will be needed along with tuning.
When I did my build in 2014 with 66,000 miles on the OEM L-82, I was still running the OEM Fuel pump and factory motor mounts so both were replaced with new ones. I reused comp cams roller tipped 1.5 rockers that I had put on the motor a few thousand miles prior and looked brand new. I also reused my double roller timing chain that was pretty much brand new before the tear down along with a recently installed Stage 2 Stewart Aluminum water (pretty much the best you can buy). Everything I reused and the new parts are still there today, running perfectly.
I can talk all day about the roller cam, cam button, and timing cover so I will condense this topic to a few sentences. You will get all types of comments and advice on measuring pushrods and the cam "walk" possibility with a roller cam. If you have the OEM L-82 factory timing cover-KEEP IT! Not only is the factory timing cover made of THICK steel, it sits DIRECTLY against and reinforced by the water pump housing. There is NO WAY that this cover will flex..NONE. The nylon cam button sits in the crank gear space and will rub against the timing chain cover to prevent the cam from moving forward which is highly unlikely with a super strong double roller timing chain but I did install one, just to be sure. Try bending a double timing chain in the vertical plane and see how that goes to understand my thought process here.
Yes, there will be lots of little parts big and small that will be needed along with tuning.
When I did my build in 2014 with 66,000 miles on the OEM L-82, I was still running the OEM Fuel pump and factory motor mounts so both were replaced with new ones. I reused comp cams roller tipped 1.5 rockers that I had put on the motor a few thousand miles prior and looked brand new. I also reused my double roller timing chain that was pretty much brand new before the tear down along with a recently installed Stage 2 Stewart Aluminum water (pretty much the best you can buy). Everything I reused and the new parts are still there today, running perfectly.
I can talk all day about the roller cam, cam button, and timing cover so I will condense this topic to a few sentences. You will get all types of comments and advice on measuring pushrods and the cam "walk" possibility with a roller cam. If you have the OEM L-82 factory timing cover-KEEP IT! Not only is the factory timing cover made of THICK steel, it sits DIRECTLY against and reinforced by the water pump housing. There is NO WAY that this cover will flex..NONE. The nylon cam button sits in the crank gear space and will rub against the timing chain cover to prevent the cam from moving forward which is highly unlikely with a super strong double roller timing chain but I did install one, just to be sure. Try bending a double timing chain in the vertical plane and see how that goes to understand my thought process here.
Interesting...everything I saw said I needed a new TC cover! I wish someone would make up my mind! Lol! I guess I'll find out soon enough.
My exhaust is a bit different than most C3's I have seen over many many years primarily for 2 reasons:
1. Most folks run 1 5/8 inch Long tube headers (LTH), shorty headers or stock exhaust manifolds. As you can see in the pictures attached, I have 1 7/8 inch LTH headers for the Gen 1 SBC engine that are stainless steel AND ceramic coated for heat rejection, longevity, and appearances. I don't think you can easily find 1 7/8inch LTH's for the Gen 1 SBC today that are Stainless Steel.
2. I swapped out Monza Turbo mufflers (somewhat restrictive) a few years ago for Stainless Steel Borla Corvette C4 Type S dual Square tipped mufflers which not only are pretty much straight through BUT are the only muffler that I have found have a distinctive smooth european type sound (no motorboat sounding rumble) unlike the typical magnaflow, flowmaster, etc mufflers AND are the only muffler that has a moderate idle volume, reasonably quiet at cruise allowing for easy conversation but loud when pressed. 2.5 inch pipes. Borla C4 corvette mufflers custom fitted for my C3 are extremely pricey but are very different. I stole mine for $400 on an open box deal with no damage, just a slight bend easily corrected, one 1 inch of one tip. you can se the slight damage in the first picture below on the farthest right square tip. These mufflers today are about $1500 for the pair. I just looked the other day.
Interesting...everything I saw said I needed a new TC cover! I wish someone would make up my mind! Lol! I guess I'll find out soon enough.
Hey what exhaust are you running? Like it?
The factory L-82 Gen 1 SBC timing cover is thick steel AND is literally right up against the Corvette water pump (zero clearance) to reinforce it from any movement...going on 13 years now........not a chance it flexes..NONE. Other applications do not have the same water pump/timing cover structure so "theoretically" it might flex..I doubt it with a double roller timing chain.
picture of the Stewart Stage 2 aluminum Water pump against the timing (can't slide a sheet of paper in that area) cover as the rebuild process began with disassemble pictures^^^^. There is no way that steel cover can flex.......same on new L-82 355..just prettier..LOL
My exhaust is a bit different than most C3's I have seen over many many years primarily for 2 reasons:
1. Most folks run 1 5/8 inch Long tube headers (LTH), shorty headers or stock exhaust manifolds. As you can see in the pictures attached, I have 1 7/8 inch LTH headers for the Gen 1 SBC engine that are stainless steel AND ceramic coated for heat rejection, longevity, and appearances. I don't think you can easily find 1 7/8inch LTH's for the Gen 1 SBC today that are Stainless Steel.
2. I swapped out Monza Turbo mufflers (somewhat restrictive) a few years ago for Stainless Steel Borla Corvette C4 Type S dual Square tipped mufflers which not only are pretty much straight through BUT are the only muffler that I have found have a distinctive smooth european type sound (no motorboat sounding rumble) unlike the typical magnaflow, flowmaster, etc mufflers AND are the only muffler that has a moderate idle volume, reasonably quiet at cruise allowing for easy conversation but loud when pressed. 2.5 inch pipes. Borla C4 corvette mufflers custom fitted for my C3 are extremely pricey but are very different. I stole mine for $400 on an open box deal with no damage, just a slight bend easily corrected, one 1 inch of one tip. you can se the slight damage in the first picture below on the farthest right square tip. These mufflers today are about $1500 for the pair. I just looked the other day.
There are lots of schools on thought on timing covers to use with a retro roller cam and the correct type of cam button. The are many posts here and other sbc sites on the pros and cons. I ended up using the stock cover as well with a nylon button and concluded it was an acceptable risk. As jb78l-82 said, Corvette short water pumps sit close or against the timing cover and provide some support. After 4+ years and 4K miles it has not been an issue.
There are lots of schools on thought on timing covers to use with a retro roller cam and the correct type of cam button. The are many posts here and other sbc sites on the pros and cons. I ended up using the stock cover as well with a nylon button and concluded it was an acceptable risk. As jb78l-82 said, Corvette short water pumps sit close or against the timing cover and provide some support. After 4+ years and 4K miles it has not been an issue.
Just to put a period on this question and topic for me, besides the thinking and reasoning already shared about the cam button and timing cover (I did exactly like you with the nylon cam button, OEM factory steel timing cover, and Double roller timing chain), my friend and builder of the short block and machining for my engine who is an expert GM performance builder and tuner in my area ( I mean an expert), assured me that using the nylon cam button, roller timing chain and GM steel timing cover was at ZERO risk of the cam moving forward.
Not only was he an expert GM engine builder and tuner with a mechanical engineering degree but he also when younger worked for GM as a Technical Field Trainer for their mechanics for 16 years, traveling all over the country to the dealerships to train the mechanics, as well as worked for Chrysler in the same capacity. Everything he advised me about the L-82 355 turned out to be 100% true. He knows his Sh*t!
Another way to skin that timing cover flex matter.
Timing covers can become subject to force from a camshaft's forward motion; and accompanying cam button pressing into rear of timing cover.
Insofar as it seems not mentioned, many (if not most) aftermarket Aluminum water pumps have a Design Feature to help address that potential stress on timing cover.
Look at most Aluminum aftermarket pumps; specifically at Front view, And along lower edge of casting. You're likely to find what most dismiss as a mere curiosity.
On most aftermarket aluminum sbc pumps, there is a small boss (thumbnail size) extending downward And it has an "empty" Threaded Hole in it.
Once pump is firmly bolted to block, that empty hole is perfectly aligned (by design) with CenterLine of camshaft.
That empty hole is intended for user to install a bolt or stud into it; then adjust same so as to exert a light pressure onto face of timing cover.
That pressure is intended to prevent timing cover flex; It WILL do exactly as designers intended. And, this ain't anything "new".
Water pumps are typically bolted to block with a commonly recommended torque of about 33 lb ft.
That sturdy arrangement is far in excess of what's necessary for the aforementioned timing cover brace to function as designed.
The GM-branded aftermarket aluminum sbc water pumps often have that thumbnail-size boss, But it's often yet to be drilled-tapped; user may do so as required.
