suburban radiator in a 72?

[FATRAT72]

I am in the process of putting a 454 out of a 74 suburban into my 72cstK5 and the suburban's radiator is about 2''higher than my old radiator should i make it fit ? or can i use my old radiator and shroud? Will the fan off the big block line up with my old fan shroud? thanks FATRAT72

 

[Steve_Chin]

If the Burban's radiator is 2" too tall, I don't think there is a way to make it fit. I would be tempted to contact Jerry Wirth at Rodney Red <A target="_blank" HREF=http://www.rodneyred.com>http://www.rodneyred.com</A>. I have one of his custom aluminum radiators in my Blazer and it keeps things VERY cool.

I don't think there'll be a problem with the BBC fan using the original shroud, but I haven't done the conversion.

 

[BluThndr71JMMY]

If the Sub had a 4-tier core radiator and your 72 K/5 had a 3-tier, the bottom radiator brackets wouldn't allow the bigger radiator to seat properly and it would be raised up by 1/2" at least. I had that problem when I cannibalized a 4-tier out of my (then down) 71 Jimmy into the (then working) 67 Sub. I used some thick nylon spacers to elevate my upper radiator retainers for months until I took it into a radiator shop and the guy fixed me up with the 4-row lower retainers. Then it fit fine. But I was dealing with same-generation trucks. 2" seems excessive. I'm not that familiar with the 73-87s.
<P ID="edit"><FONT SIZE=-1>Edited by BluThndr71Jmmy on 06/22/01 03:09 AM (server time).</FONT></P>

 

[FATRAT72]

Both radiators are the same width and thickness,the only difference is the height 2''taller than my blazers radiator.
Both have 3''thick cores but the suburbans has 36 fins to the blazers 32.I was thinking about using 2'' spacers on the top support it looks like the hood will still close .Do i need it for the extra cooling?thanksFATRAT72

 

[BluThndr71JMMY]

If you live in the desert like I do, you would think its a good idea. Theoreticaly every extra square inch counts. You might need to fabricate a sheet metal web joining the upper radator retainers. I saw one on a 67 pickup in a back issue of Chevy Truck magzine.This could then slope down to join the big block fan shroud. Big blocks can put out some heat.
--Just thinking out loud here...
Good luck.

 

[fatdog]

I bought my blazer with the 454 already in, and it has the factory 4 core radiator in it. However, the guy told me he used all the front of the engine parts ie: H20 pump, ribbed belt, and pulleys (not serpentine), brackets, and fan shroud off a 1986 suburban. He also used an aluminum flex fan, which I'm not crazy about (noisy), but it does cool very well. I don't know how far along with the swap you are, but he also mentioned that he ordered a set of (I think he said Hedman) hedders that would not fit. He also said he could not return them after trying for fit so, he had to eat the cost. Hence, he ordered a set of the hooker super comps, and they fit perfect. Please take this with a grain of salt, because I did not do this myself I was just told this. Just thought this was worth mention if you are going to run hedders.

Maybe someone else here can verify or shoot down this hedder disrepancy issue. Anyone?

Hope this info helps.

Rob



Proclaimed GM Junkie

 

[FATRAT72]

Big block fan shroud is 2'' taller too ,When I get the motor in I will check the stock fan to see if it all lines up if it does I will let you know.thanks for the tip on the headers the drivers side stock manifold is cracked so I need to think about a new exhaust system any way ,which will give me more power on the bottom end?headers or stock manifolds .Engine is all stock but will be adding a performance intake

 

[BluThndr71JMMY]

I don't know if I can talk Hedders here, having barely survived Heddmans on my 350/sm465 manual install with them in the Jimmy, But my 67 sub had a th350 on a 454 -- possibly because the stock manifolds allowed no room for a z-bar, let alone linkages etc. Probably the previous owner's quick and easy way of getting a truck back on the road. Who can say? I'm not a fan of automatics, however.
The stock exhaust mainifolds were cracked in a few places, and JB-Welding didn't help. It just turned to ash.
I have been told by professional drivers that the Mark IV engines were well not thought of in the manifold dept. It was regarded as design flaw. Hence the Mark V series.
At one point, I was going to upgrade my big block with JBA shorty headers and match it with an Offy intake. The intake was a rectangular port model and it turned out my heads were oval port units. Since I could not afford new BBC heads, I stayed stock. Hopefully header design has developed since.


<P ID="edit"><FONT SIZE=-1>Edited by BluThndr71Jmmy on 06/27/01 12:52 PM (server time).</FONT></P>

 

[fatdog]

Generally speaking, the stock intake & exhaust manifolds will perform just fine on a stock engine up through about 4000 rpm. I can't really say if a performance intake and headers will give you more bottom end power or not, but I doubt the addition of these parts would have too much effect one way or the other on the large displacement 454. There are a lot of variables going on here to consider ie: conditon of the engine, compression ratio, auto or standard, your avalibility of a replacement exhaust manifold, how the rest of the exhaust system will be designed, dual or single plane intake you plan on running, carb, gear ratio, tire size, $ you have to spend, and what you want to do with the vehicle. I know it sounds like I'm getting carried away here and maybe I am, but I always like to consider everything. Personally, whenever I install a used engine (I assume this is the case) I normally just use stock parts if I already have them and it is a stock engine. My wallet likes this approach. Also, if it is a used engine, I always check the compression, check the cam and lifters for excessive wear, replace the timing chain and gears, oil pump, and do a reseal (cheap insurance). I'm sorry to get so involved here, but on one occasion I failed to replace the oil pump on a 396 I swapped to a 69' 4x4, and lost the engine about two weeks later. I also had a cam lobe go flat on a used 350 shortly after I installed it. Disheartening events I assure you. Not to mention, all the additional labor involved. As a side note concerning 454 performance, the one in my blazer has the Edelbrock performer cam & manifold, Quadrajet carb., Hooker super comp headers, 2.5" pipes with flowmasters, ported oval port heads, and is @ 9.5:1 static compression ratio. I'm running a 350 auto trans., with 3.73 gears, and 33x12.5 tires. It does not have exceptional off idle performance, it is good, but not exceptional. However, it gets very strong @ about 2000 rpm. If I was going to do more down and dirty wheelin' with it, I would follow the general concensus on this forum, and lower the gears to 4.11 or 4.56 ratio. I didn't mean to go into a dissertation here about what you should or shouldn't do, I just had a lot of thoughts running through my head about my past experiences. I hope some of it will help you out.

Rob

Self and Spouse Proclaimed GM Junkie
She thinks I'm Sick and... She's Right

 

[FATRAT72]

I have a 72 cst blazer with ff14blt rear dana44hd front end 8lug to match the rear with 3.73 gearing.Running ss tsl's 33-13-16's turbo350 is going in for rebuild and a 205 transfer case.with dual exhaust2.5''but my 350sb is getting tired.I found a 74 suburban 2x 454/400/3/4ton rust bucket that ran good for $500 dollars and decided to make a swap . The 454 is on a stand right now I am pulling of the sheet metal and inspecting all parts before install allready need a new water pump,harmonic balancer,exhaust manifold.Will also be adding a new intake (Edelbrock performer rpm?)new timing chain(gear drive?) oil pump,fuel pump,belts and hoses.Plus the burb had a transmission oil cooler I will be adding to my blazer.Will be parting out burb for expenses.( I hope)plus I also think I will need a lift to compensate for the weight of the larger motor.Which should I use the stock q-jet or my edelbrock1406 600cfm?or?thanksFATRAT72

 

[fatdog]

Sounds like you made a good buy on the engine. I've never run the performer rpm manifold, so I can't say on that one. Anyone? Gear drives are nice, but I prefer the Cloyes true roller chain for a daily driver. Yea, you'll need to lift some. I'm running @ stock height now and with the 33's I get some rubbing when the suspension is compressed during a sharp turn in a mild off road situation. On the pavement is is ok though, but who wants to drive there! I plan on doing a 2.5" lift in the near future. Carbs hmmm, for most people this gets down to preference by experience. Personally, I've had good experiences with all different brands, but the good experiences resulted from learning how each carb functions along with a lot of trial and error for a particular engine. 600 cfm might be a tad small for a 454, but then again it depends how you are going to run it. Right now I have the big Q-jet on my 454 and I like it. I also have a Holley 4175 650 cfm on my GMC, with a 400 SB, and I like it also. This is one area where I truly believe proper size, model and application choices along with correct set-up are more important than brand name. Just FYI, the March, edition of Peterson's 4 Wheel & Off-Road mag. has an article of a carb shoot out between brands. They gave the Q-jet the thumbs up for overall wheelin'. They didn't like the Holleys on angles, but I've had my 4175 Holley in rather extreme angles of all directions, and it's never stalled on me yet. However, they didn't test the Holley 4175. I've also had a properly set-up Carter AFB (Edelbrock similar) in extreme wheelin' situations, and it never let me down. Do some research on carbs, and choose what you think is best for your situation and application.

Rob

Self and Spouse Proclaimed GM Junkie
She thinks I'm Sick and... She's Right