Pretty much as tittle suggest I'm considering putting an 454 big block into my 1973 G10. Currently its SBC 350cu through a 350 auto. I was hoping to drop the 454 in and hook it up to the existing 350 gearbox.
I've done a bit of digging and i am aware that there was a factory G30 in nineties. So it obviously fits to certain extend. The potential issue I think i have is that mine being a pre 78 is the earlier line of gen3, one of the changes they made between mine and the 90s models was a "larger dog house". I presuming this wasnt just the dog house itself but the hole it covers too. So I'm worried despite a BB fitting the 90s g30 it wont actually fit in mine. If its just going to need so bashing / triming then it might still be a goer but i seem to think they actually moved the frame rails to get the extra size of the dog house. I'm not really thrilled at the idea of chopping frame rails and would probably just go a different route if that was the case.
I appreciate i'll likely need to run at least the g30 spring and probably the whole cross member but thats bolt on right - even to a '73 ?
I'm hoping someone with a bit more concrete knowledge could wade and confirm if it'll fit at all and what kinda things will need done.
Sorry this seems like a bit of repeated post - ive done a search and there are a lot of threads about it, but they're all discussing the later (post 78) van
Not sure if it is of any use to you, but I just (friday) put a big block in my 92 G30 ewb. It is a tight fit... if the frame is narrower on a 73, it will be a fight... my passenger side clears the frame by about 5/16 at the exhaust manifold.
85 Chevy SWB G20 292 w/ 3 on the tree (had it in high school) 78 Chevy SWB G30 350 700r4 Pathfinder 4x4 conversion (wrecked in 08) 92 Chevy EWB G30 350 4l80e (bought with 587k miles for the body. Getting transplants from wrecked 78. Then big block) Various minis over the years.
If its just cutting the hole bigger i might still be willing, but i'm not 100% they didnt have to moved/adjust the framerails to make the hole bigger and i'm really not equipped to take on that challenge.
Wondering if someone who knows could clarify how they enlarged the hole and what it'd take for me to do it myself
Both of mine came factory so cant tell how much trouble it is .... I can tell ya if you do it you WILL LOVE IT ! ! ! I drive a 454 daily either my street machine that eats Mustangs or my 4X ..... there's NO REPLACEMENT FOR DISPLACEMENT ! When in doubt bore it out ....
Oh yeah welcome to the site ...
SUNSHINE VANS-VAN DIEGO ADRENALIN BY THE GALLON & CHASIN RACIN ONE FOR THE DIRT & ONE FOR THE STREETS '93 CHEVY G30 454 4X4 SPORTVAN EXT 146" WB '92 CHEVY G30 454 BEAUVILLE EXT 146" WB
Boring out a small block to larger capacity may be another way of achieving your goals. A 60 thou increase brings capacity to 360cu I think. But that said there are plenty of other ways to bring up the power of a small block.
"The largest-displacement small-blocks ever produced by GM are the LSX454/LSX454R crate engines offered through Chevrolet Performance, at 454 cubic inches (7.4L); the largest-displacement small-block for a production vehicle is the 427-cubic-inch (7.0L) LS7 used currently in the Corvette Z06"
are you just doing it for the conversation factor? do you have a big block already?
I don't know what your budget is, or even what is available to you over there across the pond, but the LSx based engines are a pretty easy swap and will give you years of power and dependability. They are fairly cheap now over here and easy to come across without too many miles on them.
you also have the advantage of the over 150lbs less weight over the front wheels!
I dont already have a block. I was kinda wanting to do it for the cool factor, everyone should rebuild a big block at some stage.
I was wanting buy a second hand hand BB, strip it right down, get the crank ground, bores honed and a performance top-end rebuild kit. Nothing too extreme but i thought if i started with a 454 i could expect around 500bhp without going too nuts. Other than the machining work I was hoping to do most of the spanner-ing myself over a period of months. Eventually dropping it in around next spring. I'd budgeted around £5k for the rebuild itself, ball park figures obvs. I'd come round to costing out the fitting. Cos i already knew there were factory big-blocks i'd just assumed it was more or less plug and play... but now it seems its not cos the age of my van. I'd rather not go chopping frame rails etc so I think my van isnt destined to have a BB.
I appreciate I can do a similar thing with the small block and actually probably make similar power, but there is something about a BB to my mind. The van already has a carb/inlet/cam, I might just do a head swap and call that a do for the van - getting no where near my 500bhp. Then maybe find another than will take a BB and come back round to that project.
I really like my van, and I'm not really up for hacking it about. From what I've seen putting an LS in there isnt drop in either. I'd rather just have a warmed over SBC.
I'm just glad i asked before I'd put all the effort into the new motor, only to find it didn't easily fit.
Thanks for all the replies really appreciate the input
thanks for the video link! I will definitely look back at it if I ever do an LS swap.
it looks like if they were not using a dry sump oiler and had a 78+ opening, they wouldn't have had to do any cutting. I know that my dad had to do some cutting to mount an LS into his 57, but he wanted to keep the F Body Low mount accessories (AC, ALT, etc), and I think that was the only reason he needed to make room. he also had to modify the oil pan to clean and work with the Rack and Pinion system he also used. Now, you can buy aftermarket pans to fit basically everything.