Author Topic: Need more grunt from 454  (Read 1898 times)

Offline 77c10diesel

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Need more grunt from 454
« on: November 24, 2017, 12:18:11 PM »
I have an 85 K30 dually cab and chassis with a service box. It is a 4x4 with a 205 and a THM400.
I got this to tow a 34ft trailer.  It has no smog stuff due to it being a K30 C&C. It has a Rochester 4 barrel on the stock 454. And, it has 17K original miles.
I need to get a little more power from this truck. I would rather not due any internal engine stuff due to the super low miles. It runs like a top, it just needs a little more gitty-up.
Oh, and it has 4.11 gears front and rear.
Would I benefit from a different carb, intake and cam swap? If so, what do you suggest?
There is no smog pump, so the stock manifolds are not restricted by the smog injectors. I would like to keep the stock iron manifolds if I can.
So, any suggestions that would boost the torque and HP a little?

Offline VileZambonie

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Re: Need more grunt from 454
« Reply #1 on: November 24, 2017, 01:17:38 PM »
Try advancing the timing before you do anything else.

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Offline zmanabba

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Re: Need more grunt from 454
« Reply #2 on: November 25, 2017, 12:09:50 PM »
I agree on the timing. A faster advance curve would help also I could give a suggestion for a performance curve but with you towing that trailer I am not sure you want it to come in that quick. With your reluctance to go inside the engine (not shaming I understand with those low miles ) most of the improvements will be hampered. A camshaft change would really wake it up like a Voodoo #10110702 if you ever change your mind. There might be an improvement with an intake change you have the pancake style right now. Try to find an old style q-jet intake if you want to go the factory route. The older style were more the high rise style. A high rise aluminum dual plane with the q-jet bolt pattern if you don't want to wrestle cast iron around ( I am 55 I like that choice lol). Keep the Q-jet it is the 800cfm version if it's original. Cliff Ruggles book on Quadrajets has some excellent tuning and rebuild instructions. A quality set of headers and a free flowing exhaust would help considerably. If you are dead set on the exhaust manifolds a set of better flowing mufflers at the very least. I have the same driveline in my K10 SWB and enjoy it daily. David 

Offline Willy Lee

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Re: Need more grunt from 454
« Reply #3 on: January 08, 2018, 10:49:04 PM »
The horrible compression ratio and crap heads are what’s hurting this set up. Putting a cam in it with heads that will only choke out any performance gain you would of gotten. Big block like to breathe and those heads are like you breathing threw a straw. A turbo would help. The low compression will work with a turbo and the air will be pushed threw. With a turbo you have good driving majors and power when you need it.
« Last Edit: January 08, 2018, 10:51:30 PM by Willy Lee »

Offline Big Chip

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Re: Need more grunt from 454
« Reply #4 on: January 09, 2018, 04:50:15 PM »
The horrible compression ratio and crap heads are what’s hurting this set up. Putting a cam in it with heads that will only choke out any performance gain you would of gotten. Big block like to breathe and those heads are like you breathing threw a straw. A turbo would help. The low compression will work with a turbo and the air will be pushed threw. With a turbo you have good driving majors and power when you need it.

The sounds like a great idea.  Have you done many BB turbo setups?  I would just be worried with all that extra power a guy may have problems with the driveline. What's your experience with that?  I am very interested.

Offline Willy Lee

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Re: Need more grunt from 454
« Reply #5 on: January 09, 2018, 05:04:48 PM »
The horrible compression ratio and crap heads are what’s hurting this set up. Putting a cam in it with heads that will only choke out any performance gain you would of gotten. Big block like to breathe and those heads are like you breathing threw a straw. A turbo would help. The low compression will work with a turbo and the air will be pushed threw. With a turbo you have good driving majors and power when you need it.

The sounds like a great idea.  Have you done many BB turbo setups?  I would just be worried with all that extra power a guy may have problems with the driveline. What's your experience with that?  I am very interested.
as long as you don’t put a sissy 700r4 behind it and keep boost down to like 6 psi. Anything higher then that you may run into converter issues. You’d need one with an anti ballon game plate. If your gonna do it with a 10 bolt id go with an 89-91 Burb or Blazer rear axle and if 4x same years 10 bolt front axle too. They make carb kits to convert a Holley to be used as a blow threw carb. I wouldn’t use a Slobberjet or Edelturd.

Offline Big Chip

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Re: Need more grunt from 454
« Reply #6 on: January 09, 2018, 05:09:44 PM »
The horrible compression ratio and crap heads are what’s hurting this set up. Putting a cam in it with heads that will only choke out any performance gain you would of gotten. Big block like to breathe and those heads are like you breathing threw a straw. A turbo would help. The low compression will work with a turbo and the air will be pushed threw. With a turbo you have good driving majors and power when you need it.

The sounds like a great idea.  Have you done many BB turbo setups?  I would just be worried with all that extra power a guy may have problems with the driveline. What's your experience with that?  I am very interested.
as long as you don’t put a sissy 700r4 behind it and keep boost down to like 6 psi. Anything higher then that you may run into converter issues. You’d need one with an anti ballon game plate. If your gonna do it with a 10 bolt id go with an 89-91 Burb or Blazer rear axle and if 4x same years 10 bolt front axle too. They make carb kits to convert a Holley to be used as a blow threw carb. I wouldn’t use a Slobberjet or Edelturd.

I just bought a TH375 off a guy on Craigslist.  Is that a good transmission?  I had one of the 700r4 in my 86 and I had problems with that and that was just a 305 with an RV cam.  Nothing special.

Offline Willy Lee

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Re: Need more grunt from 454
« Reply #7 on: January 09, 2018, 05:27:09 PM »
The horrible compression ratio and crap heads are what’s hurting this set up. Putting a cam in it with heads that will only choke out any performance gain you would of gotten. Big block like to breathe and those heads are like you breathing threw a straw. A turbo would help. The low compression will work with a turbo and the air will be pushed threw. With a turbo you have good driving majors and power when you need it.

The sounds like a great idea.  Have you done many BB turbo setups?  I would just be worried with all that extra power a guy may have problems with the driveline. What's your experience with that?  I am very interested.
as long as you don’t put a sissy 700r4 behind it and keep boost down to like 6 psi. Anything higher then that you may run into converter issues. You’d need one with an anti ballon game plate. If your gonna do it with a 10 bolt id go with an 89-91 Burb or Blazer rear axle and if 4x same years 10 bolt front axle too. They make carb kits to convert a Holley to be used as a blow threw carb. I wouldn’t use a Slobberjet or Edelturd.

I just bought a TH375 off a guy on Craigslist.  Is that a good transmission?  I had one of the 700r4 in my 86 and I had problems with that and that was just a 305 with an RV cam.  Nothing special.
if you get a rainbow 700 the are a bit better but still crap a 375 middle of the road th400 is what you want. What you don’t want is a turd 305. Small blocks are for kids be a man and get a big block and quit throwing good money away.

Offline Big Chip

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Re: Need more grunt from 454
« Reply #8 on: January 09, 2018, 05:29:36 PM »
Good advice.  I have big blocks in a couple of my rigs so I know what you mean. 

Offline Willy Lee

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Re: Need more grunt from 454
« Reply #9 on: January 09, 2018, 06:36:42 PM »
Good advice.  I have big blocks in a couple of my rigs so I know what you mean.
well that’s a good thing. Small blocks are for learning and big blocks are for when you want to get serious.

Offline Dr_Snooz

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Re: Need more grunt from 454
« Reply #10 on: January 10, 2018, 06:35:18 PM »
Swap in a 4.56? It will provide plenty of power with a stock setup. Of course, you'll only ever get 8 MPG again.
1986 GMC C-2500 Crew Cab, 7.4L, TH400 -- RIP Chester

1989 Chevy Suburban V-2500, 5.7L, TH400

1990 Chevy C-3500 Ext. Cab, 7.4L, 3L80

Offline roundhouse

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Re: Need more grunt from 454
« Reply #11 on: January 11, 2018, 06:07:34 AM »
No ones suggested an LS swap yet ?

Offline GreenK30

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Re: Need more grunt from 454
« Reply #12 on: March 03, 2018, 05:37:07 PM »
I found this a good thread. Especially ' jw454 ' info:

http://forum.73-87chevytrucks.com/smforum/index.php?topic=10299.0