thinking about swappin out my 350 for a 454... need some opinions/advice

[CRYPTIC86]

My burban: 86, 2wd, 1/2 ton, 350, TH350, everything original or oem replaced.

Havent checked it out yet, but the 454 is supposedly in a similar-year suburban that is a 2wd, 3/4 ton.

I know (and love) my 350, but I don't know what to expect- good or bad- when swapping for a bigger engine. I'm assuming mods to the suspension to carry the heavier load (which might be a feat being as though my truck is already dropped). Other than that, I'm clueless... Will I need main bolt mods? Transmission mod/replacement? Anything else that isn't so obvious?

And is it even worth the trouble? Is bigger not necessarily better?

Thank ahead of time guys 

[Captkaos]

First question I would as is are you swapping for particular reason or just swapping cause you found one.

If there is no good reason to switch other than you can I would say it wasn't worth the effort.  If you want easier towing power, then that would be a good reason.

Technically swapping to it requires no modification UNLESS you don't want the front end to drop lower.
It will bolt in place of the 350, but you really need to get everything with it (accessories, exhaust manifolds)
You WILL have to change your exhaust, or severly modify it to work.
If you aren't going to be drag racing it and doing power launches, the TH350 will work, BUT if it is old it and you have a heavy foot, it won't last long.  If it has recently been rebuilt is should be fine with normal driving.  If the donor runs, get the engine with the trans. 
If you switch trans to a TH400, you will have to move the trans crossmember.
I highly recommend getting the radiator and shroud from the donor also

[CRYPTIC86]

In addition to the loads of work I've had done to my 350, the current problem is bad compression, a few bad valves, and an almost flat cam. I'm just tired of trying to stay in original mode. My first thought was to just overhaul the heads/top half, but then I know it wouldn't be long until my block gave out. Soooo I thought I'd give in and look for a new engine. The only reason I'd consider the 454 is the price; dude is selling the whole Suburban for $800. Otherwise I'd just spend the $2500 on a new [re-man.] 350.

I wouldnt mind the front dropping lower, but I already have only 2-3 inches of clearance underneath, so I was assuming it would be a good idea. Thanks for the tip on the exhaust, its about time for that anyway. And my transmission is awesome, but that's what I'm afraid of- fixing/replacing one thing just to have something else take a dump.

[choptop]

I did it on Oldyellers 81, and would do it again in a heartbeat if I was in your shoes. Im a little off tho, it think a bigblock looks right in anything.

[CRYPTIC86]

lol, thanks choptop....

i've decided that i'm just going to pick up a C10 and slowly work on the burban

[Jims86tpisub]

Cryptic...Don`t do it unless you plan on making it a permanent off road vehicle, it wont pass smog with a 454.

[SLOW-N-LOW74]

It will pass smog if he keeps all the smog equipment from the 454 when you put it in your truck. My smog tech did it to his truck and i asked him the if it will pass smog and he said if it was an option for that year it will pass no problem with the smog equipment.  hope that helps

[Jims86tpisub]

There was no 454 option in 86 in a 1/2 ton. the only option he has for a 454 would be the TBI 454 out of a 90 SS1500, as it is under 8500 GVW, and yes, he would have to retain the 1990 smog equipment.
Any engine change must be same year or newer for a 1/2 ton truck...no 3/4 or 1 ton power trains allowed.
that leaves him with the 6.2(replaced with the 6.5) diesel, or a 305 or 350.
You may want to look into getting a goodwrench replacement engine for around $1300, but that all depends on what you want to do with the truck. you could go with an 87 or later TBI 350 from a donor truck, and that would get rid of a lot of the headache prone vacuum emissions systen under the hood, and, you won`t have to change your exhaust system.

[topp]

There was no 454 option in 86 in a 1/2 ton. the only option he has for a 454 would be the TBI 454 out of a 90 SS1500, as it is under 8500 GVW, and yes, he would have to retain the 1990 smog equipment.
Any engine change must be same year or newer for a 1/2 ton truck...no 3/4 or 1 ton power trains allowed.
that leaves him with the 6.2(replaced with the 6.5) diesel, or a 305 or 350.
You may want to look into getting a goodwrench replacement engine for around $1300, but that all depends on what you want to do with the truck. you could go with an 87 or later TBI 350 from a donor truck, and that would get rid of a lot of the headache prone vacuum emissions systen under the hood, and, you won`t have to change your exhaust system.

That all depends on the state you live in.

[bmaier]

Ahh I love my state...I don't have to worry bout emissions. Only one I know about is catalytic converters.

[Irish_Alley]

in MD if you go for historic tags they just have a for you fill out with your vin and insurance policy number no card just a number and they hand you your tags right over the counter