Don't know what to do

[88chevy]

I have a 1988 Chevy K1500 IFS with a 350 and a 700r4 trans. I planning on putting a 355 small block chevy with over 400 horses. I was wondering if I had to get a better trans and bigger axles to handle it or if i'm ok with what i have, I have a 10 bolt rear axle with 3.42 gears and the IFS axle in front.

[Kodiak450r]

more then likely you'll blow up both the trans and the rear if you don't beef them up. if your gonna keep the IFS and 6 lug wheels simply get a 14 bolt semi float and it's a direct bolt in. it'll handle the power and you can retain the stock gearing. the IFS axle itself can probably handle it but you'll break other stuff first, such as cv axles. and as for the trans it's probably not gonna last long if you keep your foot in it as stock shifting is rather sloppy and sluggish unless you have a shift kit in there. i'd suggest getting the trans rebuilt with some upgrades to handle the increased power. stock power in that truck is on 200-210 so your doubling the power and torqe thats going through the whole drivetrain.

[Mudbuster]

how many miles are on the tranny if there's a lot you may wanna have it freshended up and install a good shift kit and it'll be fine, if it's a low miles tranny just install the shift kit. Trust me a 700 will hold 400 horse, I used to have an 86 chevy fullsize long box with a 425 horse (est) 383 stroker and it did pretty good for 4 or 5 years untill I pulled the stroker and put it in my jeep My brother is now driving that truck with the same tranny. I proved to a lot of nonbelievers that it would work, the only problem I had was when I had to pull out a tree to get my friends bronco out of the mud, I got the tree and my friend out but twisted my output shaft, blewa sprag and broke a planirary reaction shell I changed those three parts and resused the same cluthes

[88chevy]

The trans was rebuilt in October 07 and the guy put a mild shift kit in it and beefed it up to handle bigger tires. I don't think that the IFS would be able to handle alot of horsepower because I broke both my axles about a month ago pulling my friend out of a pond, I havn't fixed the front yet. If I fix it then it should be fine or should a look into a SAS for it.

[Mudbuster]

The trans was rebuilt in October 07 and the guy put a mild shift kit in it and beefed it up to handle bigger tires. I don't think that the IFS would be able to handle alot of horsepower because I broke both my axles about a month ago pulling my friend out of a pond, I havn't fixed the front yet. If I fix it then it should be fine or should a look into a SAS for it.

from what you just said I would think the trans should be good to go, as far as the front you say you broke both of the axle shafts if so put ne ones in and you should be good for a while, they do get old and wear out that's probobly why the broke in the first place.

[7387chevynut]

Is this your daily driver?.......if it is  not....I'd be swapping in some new axles.......1 ton 14 bolt rear.......and a straight axle dana 44 or 10 bolt front.....some fab work will be needed.....of course.....but your gonna have a much stronger axle set which you wont break so easily.  Your present Np241 T-case would work if you used a Ford (pre 79) dana 44 front..............or if you went with a chevy 10 bolt or chevy 44 front axle........you can swap out your transfer case.............for a passenger side drop Np241 (out of a 89-91 K5 blazer or suburban)......or run a older 81-87 Np208.....which is almost the same as a Np241.....and either one is a direct bolt in..........but you would have to cut a hole in the pass. side of the floor hump for the T-case lever.

Also no mention of what size tires your running..........but for axle gearing........ 4.10 should be enough to handle 35/38 inch tires...............considering also that your (soon to swap in) motor is rated at 400 horsepower

[Fraser]

Is this your daily driver?.......if it is  not....I'd be swapping in some new axles.......1 ton 14 bolt rear.......and a straight axle dana 44 or 10 bolt front.....some fab work will be needed.....of course.....but your gonna have a much stronger axle set which you wont break so easily.  Your present Np241 T-case would work if you used a Ford (pre 79) dana 44 front

it would be 77- 79 Ford 44 and/or 60 front depending on what you want, or what ya find at a good price.  semi floating 14 bolts = $$$$, and the ifs front wouldnt hold up to the power, as youve already found out

[88chevy]

Thanks for all the help guys, the truck is my daily driver and I don't have the money right now for a SAS so i'll replace the front axle and try and find a 14 bolt sf to bolt up in the rear.

[Fraser]

Thanks for all the help guys, the truck is my daily driver and I don't have the money right now for a SAS so i'll replace the front axle and try and find a 14 bolt sf to bolt up in the rear.

the semi floating 14's that ive saw have commanded a decent price, might want to save that $ towards something else, and just carry spare shafts and stuff with you

[moose1229]

it all matters on how you are going to drive it.i puit a carbed 350 in a 90 k1500 and i ran the stock axles w/35's and a snow plow w/a 6" lift and 1 ton springs