big block conversion ????

[FRANKENSTEINC10]

my small block 305 took a crap on me (go figure). I have a friend with a 454 that he is letting me get CHEAP and tranny will be TH350 for a little while. what all do I need to complete this swap on a 72? do I absolutely have to have big block frame stands? are there any specific mods that I need to do to make things easier?

[68350]

I believe you can use the small block motor mounts. Really the motor will drop right in. You will need to do things like exhaust, change radiator shroud, etc. Is motor short or long water pump? Are you getting all the accessory brackets with it?

[merlin3]

i purchased a 72 c10 with a big block after replacing the motor with another big block i could not get any headers to fit and the oil pan was hitting the front crossmember along with other issues.thanks to this forum i figured out the truck had small block frame stands after installing a set of big block stands my problems were solved.

[FRANKENSTEINC10]

I was thinking I'm gonna need the big block fram stands but they look like they cost almost as much as I'm paying for the complete engine!!
68350 I'm not sure on the water pump but yes I am getting everything.

[merlin3]

i found my stands on e-bay for i think$150.00 no problems with shipping worth every penny.

[ecgate]

I used POL's tubular engine stands and mounts to put my bbc in. I had no fitment issues at all and my headers even fit with no problems. My hei has plenty of room from the firewall. It did get real tight when I squeezed in my 4 row radiator and electric fan set up.

[jeh]

Originally Posted by ecgate

I used POL's tubular engine stands and mounts to put my bbc in. I had no fitment issues at all and my headers even fit with no problems. My hei has plenty of room from the firewall. It did get real tight when I squeezed in my 4 row radiator and electric fan set up.

I used POL tubular stands also, I was wondering what headers you used to work out ? Sorry, not trying to high jack the thread....

[ecgate]

Originally Posted by jeh

I used POL tubular stands also, I was wondering what headers you used to work out ? Sorry, not trying to high jack the thread....

I used chevelle headers. If you use these headers they are a great fit and don't hang as low as the truck headers but installing them can be a pain in the a$$. I had to hook my engine picker up and raise the motor 6 or so inches to get them in. I think the pass. side will go in with out raising the engine but the drivers side gave me a bit of a headache and required me to pick the engine up a little bit to get them in. Hope this helps.

[jeh]

Originally Posted by ecgate

I used chevelle headers. If you use these headers they are a great fit and don't hang as low as the truck headers but installing them can be a pain in the a$$. I had to hook my engine picker up and raise the motor 6 or so inches to get them in. I think the pass. side will go in with out raising the engine but the drivers side gave me a bit of a headache and required me to pick the engine up a little bit to get them in. Hope this helps.

Thanks, I will defiantly try to find a set of them. My headers hang below the frame

[Shyguy]

We used 74 big block mounts and stands when we put the '74 454 with a SM-465 transmission in my '69 frame with no problems.

[WIDESIDE72]

Originally Posted by Shyguy

We used 74 big block mounts and stands when we put the '74 454 with a SM-465 transmission in my '69 frame with no problems.

If you arent going for correct look this is the way to go as it is cheaper and better design than the pre 72 stand design. The 72 mounts are better than the 67-71 design but are more expensive. The 67-71 cushions are expensive as well!

[FRANKENSTEINC10]

ok so I found a set of the POL mounts on eBay for $120. if I'm using all factory components do I absolutely have to have the big block mounts? I already have a 4 row radiator and I plan on electric fans. could I mount the fans in front of the radiator outside of the engine bay to leave more room for the motor.

[Tom Vogel]

[QUOTE=I already have a 4 row radiator and I plan on electric fans. could I mount the fans in front of the radiator outside of the engine bay to leave more room for the motor.[/QUOTE]
Absolutely not. Fans are designed to draw, not push. I'm not sure why so many want the electric fans. If it's a stock or mildly warmed up 454, the factory fan and clutch with the factory shroud has stood the test of time for years.
Now mind you I have large dual electric fans and large aluminum rad, but I'm pushing 1100+ HP. This setup actually clears an F1R Procharger with a 10 rib belt as well as air conditioning and power steering and everything else... But just barely.
Keep it as simple as possible, GM makes some good stuff, no need to go to aftermarket if your system doesn't require it.

[FRANKENSTEINC10]

I would like to keep it all stock because the engine only has 36,000 miles on it! I just want to make sure it will fit without much modification. I could probably move the radiator back about 2.5 inches to help with clearance but my main concern is the frame mounts. I've been told and read that it will work either way.

[hugger6933]

Of the three trucks I am building two are gonna be with a 454. One already has a big block it is a 68 model the other is a 70 and I am gonna use the later 73 and later style mounts as I am not as concerned with being period correct, even to the point of the thought has come to me to change out the 68's for the later style ones as well. Jim

[Terry Crist]

You can get electric fans that are pullers or pushers and you can get some that you can set up either way.

I would rather not use pusher fans just because I would not want something blocking the passageway to the radiator. Seems a bit redundant to me.

[FRANKENSTEINC10]

hugger6933 I'm not concerned about being period correct either. but what are the benefits of the big block mounts? what would the drawbacks be to not using them?

[WIDESIDE72]

Originally Posted by FRANKENSTEINC10

hugger6933 I'm not concerned about being period correct either. but what are the benefits of the big block mounts? what would the drawbacks be to not using them?

You will have exhaust manifold/ header clearance issues if you try to use sbc towers with a bbc. Do a search on this forum for "big block swap" and other similar terms. This swap has been done and discussed here numerous times.

[hugger6933]

Yeah, if you try to use headers or exhaust manifolds that are close to the right ones for our trucks with the small block mounts, your might as well save time and just go to the shop now and hit your hand with the ball-peen hammer. It will save time and probably be less painful.it just will not fit properly. Jim

[FRANKENSTEINC10]

ok so I've seen that I can use mounts out of a 73-87! is there a special big block in those years also or did gm pull their heads out of their asses after 72 and start making sense?? if so I will just go to the pick n pull and rip some out of a square body.

[69SCSS]

Just grab a pair of Big block stands for 67-71 trucks and use small block motor mounts. You'll have to just get a couple of bolts and large washers, and you can bolt the engine right up. They'll also clear the headers. It'll put it in the right place, won't need to mess with the radiator location, just make sure you have the right fan shroud for a big block, the correct shifter rod, and the right Power steering pump for a big block (they're different). You can use the stock BBC fan also. Hope that helps.
There's a guy on here that has a full writeup about using the SBC mounts on the BBC stands, TX Firefighter is his name on the board, here's the link: http://67-72chevytrucks.com/vboard/s...d.php?t=122645

[MARKDTN]

What is the 454 out of? Is it a later model out of a pickup? Tall deck out of a school bus? Rebuilt out of a Chevelle? A 454 can be 200hp or 450hp and run on 87 or have to have race fuel. If you sit down and count the cost of a BB swap with exhaust and the stands and radiator and all the other stuff that goes with it, you are well on your way to an LS swap. The TH350 will live for a while, but eventually you will need a bigger transmission which means a new driveshaft, etc. I would consider to just pony up for either 1) a different small block that will just bolt right in or 2) an LS swap and have mileage and power-especially if the 454 is nothing special. My .02

[FRANKENSTEINC10]

thanks guy for all the info. I managed to find a guy parting out an 84 and talked him in to pulling the frame mounts of for me. cone to find out he was less than 6 minutes from my buddy's house where I was picking up the motor so I didn't have to go out of my way. $40 later and they were mine. I also found out the stock manifolds weren't in good enough shape so after I picked up the motor I hit Craig's list for some big block headers. after scrolling through 400+ post I found a set of 70 chevelle headers for $50. the guy has so many part that he through in a set of moroso valve covers and a huge air cleaner for free!!! all in all a pretty good weekend. I wish I were furth in to the project but this time raind I'm going to take my time and do it right.

[FRANKENSTEINC10]

dropped it in for a test fit and to mark the location of the mounts!

[FRANKENSTEINC10]

I know you guys love pics so I will post some more when I get home!