1991 TBI 350 Roller or Hydraulic Tappet?

[jade]

Does anyone know if a 1991 TBI 350 4 bolt main out of a 91 K5 would be a roller or hydraulic tappet cam? since I only have the top end off, how would I tell?

 

[BGKYK5]

If you have the manifold off you should see the stamped spider that retains the roller lifters in the valley. I don't think '91 truck engines had roller lifters, but somebody who knows for sure is bond to chime in any second....

 

[GNERGY]

My 91 350 burb motor was a regular hydraulic lifter motor.
Tarey

 

[jade]

hmmm. I guess it must be a tappet then because the lifters are are hydraulic but i heard somwhere that you could have a roller cam with hydraulic lifters.

 

[BGKYK5]

You can have:

Mechanical Flat,
Mechanical Roller,
Hydraulic Flat,
or Hydraulic Roller

It sounds like you have hydraulic flat, but IIRC the block should be roller ready.

 

[jade]

thanks for the info. This is my first engine build so not sure what I need yet. Bought it from a guy who said it was rebuilt. got for $200 so can not complain. Any thoughts on keeping the stock heads and cam or better to swap out for some aluminum heads and bigger cam. Its a daily driver and weekend off road toy.

 

[jade]

also noted that the engine is pretty clean and I can still see the cross hatch marks on the cylinder walls. Its been bored .030 over

 

[GNERGY]

Unless you are going to run some high rpm's keep the stock heads and put a cam in it. Then intake and some headers. If you can still see the cross hatch, the block and pistons should still be good.
Tarey

 

[wayne]

It should also be 2 bolt mains. Look here for some good info.

http://www.tbichips.com/truckmods.htm

 

[jade]

the stock heads are pretty restrictive. Is it better to open up the ports, bigger valves, etc? I am looking for around 350 HP and around 350+ ft lbs. going to run a carb instaed of the TBI. Any ideas or suggestions is greatly appreciated

 

[jade]

its actually a 4 bolt main

 

[4X4HIGH]

Truck engines did not get roller cams until 1996 when the vortec V/8 was introduced. Your 91 block will be ready to swap a hydraulic roller into though should you decide to go that way.

 

[sweetk30]

http://coloradok5.com/forums/showthread.php?t=238592

look-here