SB --> BB help - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Trifelynn · 03-30-2005, 02:39 PM

Hey guys, I know there has been some guys that have put a BB in their blazer. I might of happened across a 396...and was wondering if it is worth the trouble(as far as installing the motor) to get?

If someone could tell me what is involved in this change, it would be great...
thanks

Bluegoose972 · 03-30-2005, 02:57 PM

I installed a 454 in my blazer. It seems like every installation is a little different on what works and what doesn't. You may want to search for the following users:

Bluegoose972
Orangeuavol

I'm sure there are more, but those are the ones that jump out at me right now.

For mine, I used the small block mounts and shifted the cross member forward by 2" to gain clearance at the firewall. Some people use a hammer to knock in the firewall enough to clear the distributor and others have used body lifts.

My biggest problem was with the headers. I was never able to find a set of headers that would clear the frame and the small block crossmember. I'm planning on using stock exhaust manifolds. After thinking about it, that is probably the best anyways. I'll loose a little top end flow, but I'll not have the maintenance or heat issues that are typically associated with headers.

Good luck...Would love to see pictures

Goose

meathead95 · 03-30-2005, 04:01 PM

if you decide to get it i have a set of nos frame towers if you need them

Trifelynn · 03-30-2005, 04:12 PM

This may sound stupid...but what are those for?

AK|Bandit · 03-30-2005, 05:56 PM

Quote:

Originally Posted by Trifelynn

This may sound stupid...but what are those for?

Not stupid...he's referring to motor mounts...

Trifelynn · 03-30-2005, 11:25 PM

ahhh...thanks

I have never heard them called that <shrug>

learned something new today...

thanks

71swb4x4 · 03-30-2005, 11:56 PM

One thing you need to keep in mind is that some of those people may have body lifts which would help them. Since you have a 2wd things may be a bit different, but you also don't have the front differential to deal with as far as oil pan clearance goes.

junksaver · 03-31-2005, 12:15 AM

Hey I'm new to the board and this is my first post. I also have a 71 2wd blazer that I'm putting in a 454. It was originally a 6 cyl. I switched over to small block frame mounts at first, but I thought the motor sat to low and to far foward. I have now put in some mid 70's frame mount and think the motor sits in there a lot better. My project is still a very long ways from completion, but I could send you some pics if you need them. From all the reading I've done as well as all the pics I've searched, these motors seem to sit differently in different trucks, especially 2wd and 4wd.

71swb4x4 · 03-31-2005, 12:18 AM

Welcome to the board - you should start anbother thread and tell us about yourself, and you truck

Where are you from?

junksaver · 03-31-2005, 12:22 AM

Thanks I'll do that.

AK|Bandit · 03-31-2005, 01:44 AM

I'll be swapping in a 396 also, but my K5 is a 4x4. I'm using the SBC mounts as they will work with the BBC. I have an automatic tranny but I remember reading about manual transmission equipped trucks having clearance issues with the manual linkage. Dont quote me on that though

MAC67 · 03-31-2005, 11:18 AM

i put the 468 into the blazer , but i had a 3 inch body lift , used the small block mounts ect and left the crossmembers where they were , just had to dimple the fire wall slightly for a set of tall moroso's to clear , if you contact yukon jack he put a bb into his pickup and cut the fire wall and built some pocket type panels to sit in , looks very clean and neat , the dimples i had to put in are barely half the size of a golf ball , for headers i had to use a set of 73 up 454 bb headers that i had layin around pass side went on fine but i had to heat certain areas on the driver side header to get it to fit correctly took maybe 15 minutes

AK|Bandit · 03-31-2005, 12:48 PM

Yep, I'm still on my fruitless search for the "miracle" headers that will just slide into place with no modification needed

I also have a 3in body lift which I'm hoping will aid in the ease of fittment. The 396 I'm putting in has a massive 10 quart oil pan so I'm looking for a new low profile 5 or 6 quart one to replace it so I dont have any crossmember issues.

Gyva · 03-31-2005, 10:33 PM

If you don't want to move your crossmember up a points dist. will work and if you have a HEI a 5 pound mini sledge will persuade the fire wall to allow it to fit, if your not worried about little dent in your firewall (Mine came with a 396 and this is what the previous owner did to make it fit) it had regular 3 bolt motor mounts that worked fine... I've had regular stock manifolds and headman headers that fit as well on that 396.... but like someone said above maybe every truck is a little different? maybe my crossmember was already moved when I got the truck??? I'll have to look now that I'm thinking about it....

Kleantouch · 04-09-2005, 09:55 PM

Just got around to reading this thread- 71 K5 auto, no lift, I swapped my 350 for a 454- used sbc motor mounts, moved my engine/trans 1" forward so I wouldn't have to modify the firewall- sbc motor mounts are bolted to the crossmember, so make sure your oil pan will clear- didn't want to hit the firewall as it was already painted- Bought a set of Hooker Super Competiton metallic coated from Summit, slid right in, no adjustment, rubbing, I was surprised!- in fact I was out running around in it today with the top off- 6mpg, but what a feeling-Good luck with your swap!

Remember- "there's no replacement for displacement!"

nathan_454 · 04-11-2005, 02:11 AM

I have a 468 in my 71 4x4 K5, i dont have any body lift. i used small block mounts, im running the big hei distributor and it fit ok. i have a 4 speed and the z-bar (link) had to be re-built a little bit. we had to clearence for the valve cover on the drivers sdie a little bit, I have headers and they fit flawlessly. they are hedman part number 691110 or 69110. i cant remember which. they are for a 1st gen 4x4 k5 with a big block. other then that it was gravy.

03-30-2005, 02:39 PM	#1
Trifelynn Registered User Join Date: May 2004 Location: Williston, North Dakota Posts: 469	SB --> BB help Hey guys, I know there has been some guys that have put a BB in their blazer. I might of happened across a 396...and was wondering if it is worth the trouble(as far as installing the motor) to get? If someone could tell me what is involved in this change, it would be great... thanks __________________ Always looking for a 2wd blazer

03-30-2005, 04:01 PM	#3
meathead95 computer illiterate Join Date: Jan 2001 Location: Des Moines, IA Posts: 6,446	if you decide to get it i have a set of nos frame towers if you need them __________________ 72 2wd blazer 72 swb 4x4

03-30-2005, 04:12 PM	#4
Trifelynn Registered User Join Date: May 2004 Location: Williston, North Dakota Posts: 469	This may sound stupid...but what are those for? __________________ Always looking for a 2wd blazer

03-30-2005, 11:25 PM	#6
Trifelynn Registered User Join Date: May 2004 Location: Williston, North Dakota Posts: 469	ahhh...thanks I have never heard them called that <shrug> learned something new today... thanks __________________ Always looking for a 2wd blazer

03-30-2005, 11:56 PM	#7
71swb4x4 Senior Member Join Date: Nov 2003 Location: Brookings, SD Posts: 10,497	One thing you need to keep in mind is that some of those people may have body lifts which would help them. Since you have a 2wd things may be a bit different, but you also don't have the front differential to deal with as far as oil pan clearance goes. __________________ Some people are like slinkies, they aren't good for anything, but you can't help but smile when you see one tumble down the stairs.

03-30-2005, 02:57 PM	#2
Bluegoose972 Registered User Join Date: Apr 2003 Location: Lubbock, Texas Posts: 248	I installed a 454 in my blazer. It seems like every installation is a little different on what works and what doesn't. You may want to search for the following users: Bluegoose972 Orangeuavol I'm sure there are more, but those are the ones that jump out at me right now. For mine, I used the small block mounts and shifted the cross member forward by 2" to gain clearance at the firewall. Some people use a hammer to knock in the firewall enough to clear the distributor and others have used body lifts. My biggest problem was with the headers. I was never able to find a set of headers that would clear the frame and the small block crossmember. I'm planning on using stock exhaust manifolds. After thinking about it, that is probably the best anyways. I'll loose a little top end flow, but I'll not have the maintenance or heat issues that are typically associated with headers. Good luck...Would love to see pictures Goose

03-31-2005, 12:15 AM	#8
junksaver Registered User Join Date: Mar 2005 Location: Durham NC Posts: 216	Hey I'm new to the board and this is my first post. I also have a 71 2wd blazer that I'm putting in a 454. It was originally a 6 cyl. I switched over to small block frame mounts at first, but I thought the motor sat to low and to far foward. I have now put in some mid 70's frame mount and think the motor sits in there a lot better. My project is still a very long ways from completion, but I could send you some pics if you need them. From all the reading I've done as well as all the pics I've searched, these motors seem to sit differently in different trucks, especially 2wd and 4wd.

03-31-2005, 12:18 AM	#9
71swb4x4 Senior Member Join Date: Nov 2003 Location: Brookings, SD Posts: 10,497	Welcome to the board - you should start anbother thread and tell us about yourself, and you truck Where are you from? __________________ Some people are like slinkies, they aren't good for anything, but you can't help but smile when you see one tumble down the stairs.

03-31-2005, 12:22 AM	#10
junksaver Registered User Join Date: Mar 2005 Location: Durham NC Posts: 216	Thanks I'll do that. __________________ 68 4wd Stepside 69 2wd Stepside Project 71 2wd Blazer Project 72 2wd 3/4 Ton Project or Parts? 73 4wd Blazer

03-31-2005, 01:44 AM	#11
AK\|Bandit Registered User Join Date: Oct 2004 Location: Eagle River, Alaska Posts: 44	I'll be swapping in a 396 also, but my K5 is a 4x4. I'm using the SBC mounts as they will work with the BBC. I have an automatic tranny but I remember reading about manual transmission equipped trucks having clearance issues with the manual linkage. Dont quote me on that though __________________ It's better to wear out than rust out!

03-31-2005, 11:18 AM	#12
MAC67 " SHOW ME" Join Date: Jan 2003 Location: shelbyville illinois Posts: 2,624	i put the 468 into the blazer , but i had a 3 inch body lift , used the small block mounts ect and left the crossmembers where they were , just had to dimple the fire wall slightly for a set of tall moroso's to clear , if you contact yukon jack he put a bb into his pickup and cut the fire wall and built some pocket type panels to sit in , looks very clean and neat , the dimples i had to put in are barely half the size of a golf ball , for headers i had to use a set of 73 up 454 bb headers that i had layin around pass side went on fine but i had to heat certain areas on the driver side header to get it to fit correctly took maybe 15 minutes

03-31-2005, 12:48 PM	#13
AK\|Bandit Registered User Join Date: Oct 2004 Location: Eagle River, Alaska Posts: 44	Yep, I'm still on my fruitless search for the "miracle" headers that will just slide into place with no modification needed I also have a 3in body lift which I'm hoping will aid in the ease of fittment. The 396 I'm putting in has a massive 10 quart oil pan so I'm looking for a new low profile 5 or 6 quart one to replace it so I dont have any crossmember issues. __________________ It's better to wear out than rust out!

03-31-2005, 10:33 PM	#14
Gyva Registered User Join Date: Jan 2005 Location: Mountain Home Idaho Posts: 544	If you don't want to move your crossmember up a points dist. will work and if you have a HEI a 5 pound mini sledge will persuade the fire wall to allow it to fit, if your not worried about little dent in your firewall (Mine came with a 396 and this is what the previous owner did to make it fit) it had regular 3 bolt motor mounts that worked fine... I've had regular stock manifolds and headman headers that fit as well on that 396.... but like someone said above maybe every truck is a little different? maybe my crossmember was already moved when I got the truck??? I'll have to look now that I'm thinking about it....

04-09-2005, 09:55 PM	#15
Kleantouch Registered User Join Date: Jul 2004 Location: Lake Charles LA Posts: 138	Just got around to reading this thread- 71 K5 auto, no lift, I swapped my 350 for a 454- used sbc motor mounts, moved my engine/trans 1" forward so I wouldn't have to modify the firewall- sbc motor mounts are bolted to the crossmember, so make sure your oil pan will clear- didn't want to hit the firewall as it was already painted- Bought a set of Hooker Super Competiton metallic coated from Summit, slid right in, no adjustment, rubbing, I was surprised!- in fact I was out running around in it today with the top off- 6mpg, but what a feeling-Good luck with your swap! Remember- "there's no replacement for displacement!"

04-11-2005, 02:11 AM	#16
nathan_454 Registered User Join Date: Feb 2003 Location: Centralia, Wa Posts: 109	I have a 468 in my 71 4x4 K5, i dont have any body lift. i used small block mounts, im running the big hei distributor and it fit ok. i have a 4 speed and the z-bar (link) had to be re-built a little bit. we had to clearence for the valve cover on the drivers sdie a little bit, I have headers and they fit flawlessly. they are hedman part number 691110 or 69110. i cant remember which. they are for a 1st gen 4x4 k5 with a big block. other then that it was gravy.



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