Best HP options for my 88 4x4 K5

Hello guys im new to posting, bt not to the forum. I have a 88 K5 blazer w/stock 350. It has a built 350 turbo trans, 11" lift w/ 42's, 14 bolt in the rear & I believe it has 488's. The only kind of performance add ons would be the headers & flowmasters. Its starting to smoke a little which gives me an excuse to jerk it out & give it a few more horses. Its completely an off road mud toy, no emmissions to consider.
My question is whats my best bet to get the most hp, either out of my tbi 350, os I also have been looking at swapping in a mid 90's vortech engine, or even a 5.3 or 6.0. I have heard the LS swap is a real pain. I dont want to spend a boat load. I just want the most bang for my truck (K5). Any help would be greatly appreciated. Thanks in advance!! JP also I would like to keep it fuel injected.  

Hi There,
 Have a look at GMPP's Ram air 350 motor.
 Nice little package with flat torque
 to match those low gears.  Good luck...Skyeking  
skyeking

I think with 42" tires and 4.88 gears you are only turning around 2400 rpm's @ 60 mph. You should be looking at an engine that will make the most torque you can muster especially if you are running in the mud or climbing hills. If you look at some of the engine builds in CHP magazine you will see that big HP numbers only come at big RPM numbers. Vortec heads from a newer small block will do wonders for your motor (along with matching intake) and a cam made to produce max torque for your use (call a cam manufacturer, they will be glad to help). good luck  

I have been leaning towards the vortech, especially since  I have found one for around $200 complete, just needs rebuilt. Im also going to do a little more agressive cam, roller rockers & lifters, & maybe even turn it in to a 383. I read a post last night about a guy did a 383, but was having a lean issue. I was worried about losing the tbi to a carb, or have to spend a couple thousand on an aftermarket fuel injection, but that info helped alot especially the list of different LB injectors & the vehicles they came in. You guys are awesome on this forum & I appreciate all the input. Thanks again JP from OK!  

Your absoulutly correct on that swap. You really need a truck chassis of the late 90's and up. It can be done but thats up to you.

Hi- Skyeking!

The Skyman has you pointed in the correct direction. I would diffently look to the RAM AIR 350. Remember we are here to give suggestions, there are so many wyas to make power today its unlimited! To have torque at low RPM you will run out of top end power real quick....How about a BIG BLOCK?.......

Any direction you go you may have to change rear gears and a cam to get the horse power back up in the range of those TALL TIRES. I'll bet 5:13's up.
Good Luck.....Have fun....
Thanks
Bob  

Just remember, Vortec heads are limited on valve lift potential unless you have a little work done so the springs won't bind at higher lift.  

It isn't coil bind that limits lift.,. the retainer makes contact with the lip seal around .480" lift.
In stock form, Vortecs will handle .460" lift.,. trimming/machining the guides and installing umbrella seal, increases lift potential to .500" plus.

 
When The Flag Drops,,,



The Bull Chit Stops,,,

P. Engineer.,. Engine Builder

Hi there OLDE Blokes!!!!  
skyeking

Vortec 350s are good but,,,,,,,,,,,,,,,

Mud trucks love big blocks, >>>>period<<<<   and being strict off road I would use no less.

If you can find a junkyard truck 454 for cheap, and rebuild it.  Even a stock mild big block will eat any comparable small blocks lunch.

If you found a good engine you can rebuild it for a few more dollars than the small block.

oh and it will bolt right in place of the small block on a truck, there are no modifications to install it, even the motor mount brackets are the same.  However the accessories are different so be sure to buy a complete engine will all accessories.




If,,,, you just gotta have the small block,,,,,,,,,,, yes a vortec engine with a .488 cam (heads machined to accept lift) aluminum intake
quality 4bbl 650 cfm
headers
roller tip rockers
valve springs to match cam
(use care when selecting pistons) Flat tops will push the limit with cheap gas, vortec heads are 64cc.  

i agree chevelle83 big block will give you all the tork in the world and they are easy to come by at least wear i am just the other day i bought a set of cylender heads for 20 bucks, the guy didnt want them and i am going to rebuild them with better springs lifters ect, but yes big block is the way to go specially for mudd  

Mike

Ask him if he has 32 or I'll settle for 16 (0) small block Chevy rocker arms. If he has them?The (0) is on thevalve spring end. It's marked like the (V)on the newer ones.    

+3 on the big block....it's not like you're worried about fuel milage or anything.  
"Beat it like a red-headed FORD"

No im not at all worried about fuel mileage. I have thought about a big block. I read a little about the vortech 454, & how too get quite a bit of torque out it. I know im stuck on fuel injection it just seems like the way to go on a mud truck that climbs steep hills & is very rarely driving level. I could be wrong, but most everyone that I have seen in the mud & rock competitions run EFI. I do apreciate all the input & ideas. Also I have a turbo 350 trans that has been built. Will the big block bolt up to it without modification. Thanks again!!  

JP yes the big block will bolt right up to th350 trans.  And yes the late model 96 and later vortec 454s make excellent power and they are all roller cam blocks!  you would love it even if it were stock.  A friend of mine just bought a 98 dually with the vortec 454 and it runs great.

Ok I agree with you on fuel injection for off roading if you can afford it.  I recommend getting one of the new fast ez EFI units they cost around the $2000 mark and have minimal wiring, so check them out.

I do have an original stock efi from a 1990 suburban 454, I have the whole package if you want it I would sell it to you cheap.  How about $75 plus shipping it comes with everything but the fuel pump, and I would use an aftermarket new one anyway.

Next in line (just my personal opinion) is a well built quadrajet, I run them on everything from 305 to 502 cubic inches with no trouble.

the float is in the center of the q-jet which makes is great for off road cause the angle have "less" affect on it, other carbs will either starve for fuel or flood with steep hills or lots of bouncing around.

However on a VERY steep situation it can cause problems with basically any carburetor simply cause they have floats.  

The K5 is already fuel injected /tbi. Is their an advantage to using the tbi off a 454, (more fuel, better throttle responce or ?) Im trying to weigh all my options, I would like to do a big block, but I found a vortec 350 for $200 so thats probably what Ill do, Of course I will rebuid it & do a cam, roller rockers & whatever else I feel Like it needs when the time comes! Thanks for the info. JP