Okay, so I've done a good bit of searching on this forum and others and I still have some questions.
I am in the middle of an LSA install on my 98 ecsb and i am going to run out of fuel pump really quick. Here is a brief mod list for reference.
Gen3 lq4, 243's milled .030, pat g spec'd cam, 1 3/4" LTs, 4l80 w 2800 stall.

I found a really good write up on a 255 install in the factory bucket but I haven't seen any thing about a 450.
Installing a Walbro pump into a 98 carrier | GMT400 - The Ultimate 88-98 GM Truck Forum
Are they similar sized pumps as far as the housing/ body goes? Also, are my stock feed and return lines going to be enough for this set-up? Thanks in advance.

 

The 450 is alot bigger on the bottom and will require some modification(cutting) to the stock bucket. The stock feed and return line will suffice depending on how much power you want to make. At one point years ago, i ran my stock feed and return lines on a boosted 4.8 running over 600rwhp with no trouble.

 

Nice truck man. Did you end up doing an in tank pump on your truck?

 

Yes i run intank pump still on mine. I now use -8an feed and -6an return on it.

 

Are you able to run below a 1/4 tank?

 

I normaly always fill it back up when it reaches a half tank. If i let it run lower than that and try an make a hit on the hwy then it will roll the fuel away from the pump and have a quick stumble to it. These old trucks dont work well with less than a half tank without a bucket like the newer stuff.