What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

need help from a guy that knows about 454's

D

Dakotawest25

Registered Member
Joined
May 8, 2026
Posts
32
Reaction score
14
Location
Tennessee
i know this is vague but i need help with some questions that are probably dumb to most of you experienced guys but this is my first build and i don't want to make any major mistakes. also excuse me if this isn't the proper way to ask this i've never tried posting in a forum before.
 
Dakotawest25 said:
i know this is vague but i need help with some questions that are probably dumb to most of you experienced guys but this is my first build and i don't want to make any major mistakes. also excuse me if this isn't the proper way to ask this i've never tried posting in a forum before.
Click to expand...
Ok so my budget is relatively limited but not really i'm only wanting to go the cheaper route because i like saving money as i'm sure many of you guys do. (a little bit of history and what i know about the engine) I believe i have the stock Gen VI 454 heads but the engine i'm working with was a random facebook marketplace find for a deal ($300 granted it was very rough the engine was sitting out in the weather and seized up from rust but i've since made it in my opinion a decent block) that had been modified by whoever before me (flat tappet lifters/cam, intake and carb swapped) but that's the only modifications i can identify from my experience and research. ok so now my plan is to turn it into a decent towing and pulling rig i'm replacing most of everything except for the crank and possibly the heads if you guys think it'd be a good idea to get them polished and ported now what would be your ideal setup for something like this? I.E oversized bores, domed/flat top pistons and connecting rods, cam and lifters combos.
 
If it's a Gen VI that is a Vortec block. They are pretty good blocks, in fact local machine/engine guy looks for those to build over the older ones. Don't remember exactly what he said, but they have factory roller cams, and why PO put flat tappet who knows. But roller stuff is more than flat stuff. Hopefully the rust didn't do too much damage, these blocks really can't go more than a .060" overbore (just what I was told). The heads are decent, don't think they are as good as the 049 or 781s. but they are good and already set up (springs) for a roller cam. I'd tear it down and see what it looks like inside and go from there.
 
To be clear, you’re working with Gen VI heads AND short block? Or do you have Gen VI heads and an unidentified short block?
 
b454rat said:
If it's a Gen VI that is a Vortec block. They are pretty good blocks, in fact local machine/engine guy looks for those to build over the older ones. Don't remember exactly what he said, but they have factory roller cams, and why PO put flat tappet who knows. But roller stuff is more than flat stuff. Hopefully the rust didn't do too much damage, these blocks really can't go more than a .060" overbore (just what I was told). The heads are decent, don't think they are as good as the 049 or 781s. but they are good and already set up (springs) for a roller cam. I'd tear it down and see what it looks like inside and go from there.
Click to expand...
i've torn the block completely apart minus the cam bearings everything looks pretty good just 1 cylinder i'm a little iffy about.
 
nvrenuf said:
To be clear, you’re working with Gen VI heads AND short block? Or do you have Gen VI heads and an unidentified short block?
Click to expand...
well the block for sure is Gen VI the heads i assume are but since the previous owner swapped other parts there is a small chance it could not be Gen VI heads.
 
Crank shaft too, this will remove all assumptions.
Were the bearing shells marked with an under size or the piston with a part number and over size?
 
Just a few things to consider while seeking any type of motor build advice -

-Before you purchase or decide on anything verify what you have beyond any doubt.

-Let the machine shop ( and make absolutely certain that it is a reputable shop ) tell/advise you on tolerances such as cylinder bore sizing.

-your questions about cylinder head work, piston v/s compression selection and camshaft numbers etc all must work together in harmony and match your intended realistic usage and needs not to be a desired dream list.

-In order to give basic advice you need to help paint a better picture of exactly what this motor will be in and be expected to do.
Example: when you say “towing & pulling” are you talking a Blazer hauling around a small camper or utility trailer or is this a crew cab dually pulling a fifth-wheel setup that weighs as much as an aircraft carrier ? Or did you mean sled pulling ?

-What type of transmission is this big-block in front of ?
-What gear ratio and tire size will be used because this matters just how much the motor will work and it’s cruising RPM power band scale.

-Also keep in mind that spending a decent amount of hard earned coin on refurbishing worn factory parts at the machine shop might put you in range of just buying new aftermarket components ( like cylinder heads or rotating assembly ) that are far better then any of the factory equipment. Just compare the costs before you take action.

The better we know what you have and what it will fully be expected to do the better advice can be given.

HTH’s
 
Wes Harden said:
Can you post the casting numbers from the block and heads ?
Click to expand...
Block casting number-10237297 Head casting number-101114156 from what i just researched on the heads its showing that this is a Gen V head and i think i knew this but completely forgot since i've been slowly working on the engine.
 
I have the same heads on my gen vi mercruiser block. They are truck heads gen v and 6 454 to HT502. Peanut port small valve and 118cc open chambers.
 
tarussell said:
Just a few things to consider while seeking any type of motor build advice -

-Before you purchase or decide on anything verify what you have beyond any doubt.

-Let the machine shop ( and make absolutely certain that it is a reputable shop ) tell/advise you on tolerances such as cylinder bore sizing.

-your questions about cylinder head work, piston v/s compression selection and camshaft numbers etc all must work together in harmony and match your intended realistic usage and needs not to be a desired dream list.

-In order to give basic advice you need to help paint a better picture of exactly what this motor will be in and be expected to do.
Example: when you say “towing & pulling” are you talking a Blazer hauling around a small camper or utility trailer or is this a crew cab dually pulling a fifth-wheel setup that weighs as much as an aircraft carrier ? Or did you mean sled pulling ?

-What type of transmission is this big-block in front of ?
-What gear ratio and tire size will be used because this matters just how much the motor will work and it’s cruising RPM power band scale.

-Also keep in mind that spending a decent amount of hard earned coin on refurbishing worn factory parts at the machine shop might put you in range of just buying new aftermarket components ( like cylinder heads or rotating assembly ) that are far better then any of the factory equipment. Just compare the costs before you take action.

The better we know what you have and what it will fully be expected to do the better advice can be given.

HTH’s
Click to expand...
"towing and pulling" is kind of hard to explain knowing this a blazer forum my truck isn't a blazer it is a 1992 chevy c2500 the towing capabilities isn't equal to some trucks on weight they handle but in my mind i think pulling scrap for my boss we do machining (not the engine work kind unfortunately) and we tend to have alot of shavings something like 18k pounds when we make runs to recycler so in mind something that could handle maybe 15k? as far as transmission that's a whole other ball for later since this is a engine swap. no idea on the gear ratio i believe it has a 14 bolt rear end if that helpful.
 
Block is 96 454 L29 gen vi. Should be a roller cam engine. If not it shoud except factory roller lifters and center tray.
 
Wes Harden said:
I have the same heads on my gen vi mercruiser block. They are truck heads gen v and 6 454 to HT502. Peanut port small valve and 118cc open chambers.
Click to expand...
what's your opinion on them? worth keeping? i'm just not trying to drop $1800 on a new set of aluminum heads when this engine isn't going to be perfect everywhere else.
 
Do the heads have ajustable rockers? Or just bolt them down and done style
 
There are three separate types of C2500’s in ‘92 - two are decent and both have 14 bolts on the rear cover but one is a RPO code “C6P” and has an 1” larger ring gear and full floating axles that will be way more durable.
There is a third version that also has 14Bolts on the rear cover but only has six lug nut axles and you do not want to push this version that hard - softer springs and smaller brakes.
15K on a single rear wheel truck with smaller older type brakes is risky.

Sounds like you need a basic truck type of a 454 - if you are truly searching for quality advice then you know the questions you must answer first; but if it doesn’t really matter just copy the base truck engine example.
There’s nothing wrong with the base type peanut-port engine if that’s what you need and are gonna be happy with.
 
Last edited:
You must log in or register to reply here.

Latest Posts

Top Bottom