Cowboy Tom

I got a 1991 GMC C1500 with 305 TBI, I'm looking at doing some work over the next few months such as cam, heads, intake etc,

So i know the 305 TBI trucks came with a hydraulic flat tappet cam? correct? can they be swapped to a hydraulic roller? is as simple as just swapping cam and lifters?

I'm looking at Comp Cams Thumpr camshaft and lifters #CL08-600-8

Vortec350ss

iTrader: (20)

I wish I could help but I have no first hand experience with the 5.0. I do know its a small bore motor with pretty junk heads. I would be tempted to just pull the motor and slap in a 350 with a cam.

FFDP

iTrader: (2)

I think the 96+ vortec heads will bolt on, atleast that's what the early 90's 350 guys do.

madmann26

iTrader: (7)

They will but you also have to have a specific vortec intake manifold since the intake manifold bolt holes are angled different.

someotherguy

Yep, Vortec heads are great stock head upgrades, but come with the cost of having to change the intake ($$$$) as well. GMPP's TBI intake for Vortec heads is the only one I know of and it's about $400. Add in the cost of the heads, cam, and other misc. stuff then start spending money setting up to tune the thing so it actually runs right - TBI's really do not take well to significant mods without major tuning work - you may as well have done a complete LS swap; more power for your money and believe it or not, easier.

Modding a 305 TBI these days is really throwing money away. It was throwing money away back when they were still a current engine, too, but moreso now.

Richard

madmann26

iTrader: (7)

I wouldn't waste the money on a gen1/2 motor, personally since you can find 5.3 pullouts on eBay for around $800.

To use vortec heads, the manifold is $450. Over half the cost of a pullout.

Cowboy Tom

I completely agree with at these post, yes most people throw out the 305 for a 350, yes the 350 makes more torque, and yes an LS swap would be cheaper and more power, I actually planned on doing an LM7 swap but decided I wanted to be different and do something people don't do. build a 305 TBI,
all I want is about 350- 400hp and that is possible on 305's

So does anyone know if a roller swap is as simple as swapping cam and lifter?
Cause I've heard different things, I've heard you can but also heard that u can't do a roller cam without other major mods???