made the swap

[skeet]

chevy 99 4.3 to 5.3 but have a few questions..

one i have a heating problem changed the thermostat (stock) but still overheating..

my questions before i decide to change out the water pump i was wondering the coolant cansister its from the 4.3 does this have to be changed? i noticed the 5.3 hoses are different top and bottom i was able to use the new top but the bottom didnt have the T so i used my 4.3 bottom hose and cut it to length since it has the T. i was wondering would this keep the engine from getting enough coolant to support the engine from overheating ? or may be the problem is the water pump ?

[RedHeartbeat]

Sounds like you're vapor locking. Take the top radiator hose off the radiator end and pour coolant in until it runs out the radiator. If that wasn't enough, park the truck pointed uphill and remove the two front coolant air bleed plugs until coolant runs freely out of the holes. Be sure the air bleed lines have a spot to return to in the coolant stream.

[NITROUS]

Check out this link, I just went through the same problem. LOL
Head swap problems

[1BADC10]

Red's been right before... NITROUS knows!

[skeet]

<div class='quotetop'>QUOTE(1BADC10 &#064; Jan 15 2007, 07&#58;34 PM) [snapback]79942[/snapback]</div>

Red&#39;s been right before... NITROUS knows&#33;
[/b]

well red was right again it was vapor locked the temps came down but not low enough .. still at 220 230 also with plenty of coolant, i went ahead and pulled the water pump slightly clogged didnt look good so i changed it flushed the block before installing put pump on and temps are now fine around 190 ....


p.s. thanks guys more questions to come lol