fishinnutt
1/2 ton status
I think it could stand to move forward, the engine is buried in there a bit much. I don't think you could put a transmission on there where it currently sits.
CK5
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'71 k502 The Misfit
- Thread starter fishinnutt
- Start date
fishinnutt
1/2 ton status
I have marked the holes to move the engine forward one inch and will begin completely re-designing the firewall/trans tunnel. Anyone who can keep their factory heater and manual transmission with a 502 between the rails is a genius, after what I saw yesterday I would have thought it nearly impossible.
fishinnutt
1/2 ton status
I need to get my new body bushings and body lift in the truck also after I move the engine forward so I can get a more realistic look at what needs to be done.
bp71k5
3/4 ton status
I moved my small block 3.5" forward. Maybe a big block is deeper?
Yukon Jack
1/2 ton status
A big block is a bit wider and taller, that is where the problem arises from.
Big Block
23.63" length from center motor mount hole to front of motor
7.68" height from center motor mount bolt to top of motor
22.96" wide
Small Block
21.78" length from center motor mount hole to front of motor
5.33" height from center motor mount bolt to top of motor
19.68" wide
In regards to moving the engine forward, at least on my truck it would have taken clearancing the frame a good bit if I had moved the engine forward to make the headers still fit. Moving the engine forward will also increase your front driveshaft angle a bit, depending on your amount of lift, that can become an issue. Also need to keep an eye on the radiator fan/radiator clearance. Electric fans can address that if it is a problem. Lots of little things that come up, all things that can be addressed though. But, at least for me, it was not going to be as simple as just drilling some new holes and moving the engine/tranny/transfer case forward.
Big Block
23.63" length from center motor mount hole to front of motor
7.68" height from center motor mount bolt to top of motor
22.96" wide
Small Block
21.78" length from center motor mount hole to front of motor
5.33" height from center motor mount bolt to top of motor
19.68" wide
In regards to moving the engine forward, at least on my truck it would have taken clearancing the frame a good bit if I had moved the engine forward to make the headers still fit. Moving the engine forward will also increase your front driveshaft angle a bit, depending on your amount of lift, that can become an issue. Also need to keep an eye on the radiator fan/radiator clearance. Electric fans can address that if it is a problem. Lots of little things that come up, all things that can be addressed though. But, at least for me, it was not going to be as simple as just drilling some new holes and moving the engine/tranny/transfer case forward.
fishinnutt
1/2 ton status
I will have pics by tomorrow, my decision was to remake the entire center of the firewall and leave the engine where it was. My front drive shaft length wasn't as much of a consideration if I had moved it forward due to the Atlas4sp making the front shaft longer as it was. I made enough room redoing the firewall so that I would not have to move the engine.
fishinnutt
1/2 ton status
Thanks for the solid tech, the numbers along with my pictures tell the tale. The engine is HUGE in between those rails, Chevy definitely never intended for a big block to be in between those confines. With the right tools and a little time and patience, it will live there one day soon.
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fishinnutt
1/2 ton status
I spent some time re-doing the firewall the last couple of days.
fishinnutt
1/2 ton status
I won't even think about doing the drivers side without the engine back in place. I will build the drivers side around the engine where it sits.
fishinnutt
1/2 ton status
Disregard the sharpie reminder to "beat in" as that whole portion of the floor will soon be redesigned.
Your skill and the work you have done is just amazing. Really impressive.
I think i might write 502 on my crate 350 to make me feel as cool.
I think i might write 502 on my crate 350 to make me feel as cool.
SuperDave,
I can send you my factory 502 valve covers if you'd like.....I'm going more "stealth" anyway.
Question... I may be misunderstanding something, or be thinking incorrectly, but I thought these trucks were available with big blocks from the factory...? Like bug duallies and whatnot.
Why don't those have modified firewalls? Or is the 502 a different animal that I'm unaware of???
IForgive me, as I know little-to-nothing about Big Blocks, other than that they exist.
Why don't those have modified firewalls? Or is the 502 a different animal that I'm unaware of???
IForgive me, as I know little-to-nothing about Big Blocks, other than that they exist.
dfl701
1/2 ton status
that is such a fine piece of machinery! i bet that things gonna sound NICE
Question... I may be misunderstanding something, or be thinking incorrectly, but I thought these trucks were available with big blocks from the factory...? Like bug duallies and whatnot.
Why don't those have modified firewalls? Or is the 502 a different animal that I'm unaware of???
IForgive me, as I know little-to-nothing about Big Blocks, other than that they exist.
No worries Jon,
The early Chevy pickups came with big blocks, but the 69-72 Blazers never did... it's a sad realization for guys who "assume" that a BBC should simply "drop in" to an early Blazer... it doesn't.
Nothing is ever easy, or cheap. But to victor go the spoils....once you've done it successfully you'll get "the nod" from other guys who understand what you've actually accomplished. Kind of like a secret handshake, really.
No worries Jon,
The early Chevy pickups came with big blocks, but the 69-72 Blazers never did... it's a sad realization for guys who "assume" that a BBC should simply "drop in" to an early Blazer... it doesn't.
Nothing is ever easy, or cheap. But to victor go the spoils....once you've done it successfully you'll get "the nod" from other guys who understand what you've actually accomplished. Kind of like a secret handshake, really.
To clarify what Greg said. Big blocks only came in two wheel drive pick ups. Four wheel drives have the engine crossmember slid back around three inches for clearance on the front axle and possibly to keep the front drive line reasonably long. With the crossmember slid back there is no way for the ginormous girth of the big block to clear the firewall. In a nutshell there is no easy way to make a big block fit, all the answers have draw backs.
myraley
1/2 ton status
I can vouch from my experience as well. When I bought my 72, the previous owner had swapped a big block in on top of the original small block crossmember, the one where you have to pull the engine out to take off the oil pan. I learned the hard way the engine didnt fix when the firewall rubbed through the distributor cap, releasing one of the 4 u-hooks, and causing my timing to screw up and the engine to imitate a dying elephant. I wound up lifting the engine up without pulling it all the way out, putting a Offroad design engine crossmember in with the triangular mounts from the later 73-87 frames, with the tabs dremel-cut off of one side (cause it wont quite fit with them on). It was the best move I could have made, and I can personally highly recommend that crossmember. Oh, and bigblock72 and the others are right, it was mounted into the forward holes, because the small block holes are a few inches too far back. You'll know when you have it right becuase then the fan clutch, fan blade and fan shroud all line up exactly as they would have stock.
fishinnutt
1/2 ton status
That info. is much appreciated. I will sill be moving the engine forward also just a little bit, I think it will be helpful with my drive line situation caused by the Atlas4SP.
Scottishdave-- Thanks for the encouragement, this is definitely not what I do for a living.
dfl701-- I think my neighbors are going to hear this thing coming and going. I can't wait to hear it for myself.
Scottishdave-- Thanks for the encouragement, this is definitely not what I do for a living.
dfl701-- I think my neighbors are going to hear this thing coming and going. I can't wait to hear it for myself.
fishinnutt
1/2 ton status
Spent part of today working on the trans tunnel and cutting out the start of where my transfer case will sit. The plasma cutter was the MVP of the day.
