im thinking about finding some nice cheap vette tpi heads. and i wanna know how much i should expect to pay a machine shop to machine the heads for bigger valves (2.02, 1.6) and bigger springs (1.470") so i can run my monster cam in their

 

Are we talking about the L-98 aluminum vette TPI heads?

If you want to go up to a 2.02 x 1.60" valve set you have to replace the seats in those heads.

The hot ticket for thoses heads is to install the LT4 2.00" x 1.55" light weight valves. They can go right on the existing valve seat inserts with a new valve job.

When these heads are properly ported with the above LT-4 valves they flow very good. Not much point in asking for a price in this forum. You should consult your local automotive machinist.

Know before hand what exact valve train parts and maching operations you need to get the heads in shape and ask for a complete package price.

There is a lot of machine operation and setup overlap from one operation to another that saves $$$time$ when combined together. The final price should reflect this.
Thats how you get fair economical pricing that suites both parties. You get the job done for a good price and he makes a fair profit for his time.

If you just ask how much for this and how much for that you're going to get quoted and pay full pop for each different machining operation. Some of it you can do cheaper at home with the right tooling and a good electric drill. Do the porting work yourself.

Do you really need larger diameter springs? Might be cheaper and better overall to get a better matched camshaft to the rest of the motor, then the "monster cam" you have on hand. ya may just end up with a monster on your hands.

What cam are we talking about here?

A ported, upgraded 2.00- 1.55" valved L-98 aluminum head can perform very nicely but ya have to watch the $$$economics.$$$$ Same with factory vortec heads.

 

When you add up the cost of procuring the heads and adding in the machine work, you will be way ahead to just get some aftermarket heads.

Trust me i looked into doing exactly that. Look on ebay for how much those heads go for, way too much. This is exactly why i went with modded LT1 heads. They go for 1/3 of the price.

 

I would be inclined to agree on the price. I've looked into them as well, and unless you already have a source, they aren't THAT cheap relative to what you could get, with the needed work already performed (larger valves, decent ports, valve clearance, etc)

 

Just for S's and G's, my shop charges:

110 to replace seats, another 100 to complete the valve grind (my valves) 35 bucks to resurface the heads, another 80/90 to install bronze valve guide liners...never had larger spring seats cut with them, but that would be needed for a large cam...

You then need to look into possibly cutting down the valve guides for larger lift cam...not sure if the Vette heads have guideplates and screw instuds...but thats another expense...add it all up, plus the cost of the heads, etc...you can see why dart/etc, begins to make more sense...probably flow better out of the box untouched than worked over AL Vette heads.

 

ok thanks

and the cam i was refering to was the 276 comp cams grind

540ish lift with the 1.6 rockers

 

You could use Crane Cams spring #99846. It is a stock diameter high quality spring with suitable pressure for that hyd roller cam.
Only requireing that the guide boss tops be shortened if nessessary to ensuer that there is enough clearance at max valve lift between the retainer bottom and valve seal.
It will sit on a stock 1.26"spring seat.
A ported corvette head does not flow any more at .540" than it does at .500" so a 1.6 rocker is not going to get you much.
A 1.5:1 rocker will work just fine.

This spring does cost more than Comps recommended spring set for this cam. (#986 or 987) but is a good alternative.

 

thanks. even with porting and cleaning i wont get much benifit from the extra lift?

 

The ports are just too small.

 

It's not a matter of too small. it's a matter of port shape.

All I'm saying is don't go out of your way to get 1.6 rockers for this one. Minimumal gain. If 1.6's happen to fall out of the sky, fine.

 

thanks

i did double check the flow charts, very minimal difference between 500 and 600 so i guess this cam will match the heads will, and with the hsr, im sure the velocity should be very well which also a factor

 

i cant seem to find a link where to purchase these lt4 valves. anyone wanna point me in the right direction?

 

Exhaust: 12551313
Intake: 12555331

 

53.69 EACH!? through summit? Whats going on!

 

Well yeah that too.

 

$33.56 at GMPartsDirect.com if you don't like Summit's price.

Sodium filled valves ain't cheap.

 

i dont want to spend 500 bux on valves. lol this is a budget build to get me deep into 12's

could i stilla ccomplish that with regular sized valves?