what's the actual difference between stock lt1 heads and stock lt4 heads? because i got the cc306 cam, and i looked at a head job for my current stock ones , and for full race they wanted $1500. and for a mild port it was $1100, this is including other work and parts also... valves etc. But i was wondering if the lt4 heads have more of a flow , or have a larger size port stock... would these lt4 heads be a good choice for me ? that i could later port out more possibly? i dont know much about these lt4 heads... thanks

LT4 heads have better flow and larger ports. stock LT1 heads flow about 210, LT4's flow about 250. With the 306, you can run stock heads, but you will not get any where near the power you could get from ported heads. That cam is a pretty big one for a stock cube LT1, even with ported heads. To really take advantage of it, you would need the full port job on the LT1 heads or a good port job on LT4's.


*Edit*
Ok, found the numbers.

LT1: 170cc, 1.50/1.94 valves, 212 CFM
LT4: 195cc, 1.55/2.00 valves, 240 CFM, .10" higher intake port



Here is a good site that lists all of the differences between the LT1 and LT4.

thats exactly what i was thinking, i want to get a set of lt4 heads, and get a decent port job on them later down the road. but right now i have cast iron heads , stock, so ill get the lt4 heads and run on them for my first year runnin the car, and as i save ill get them ported down the road. Just cant afford a full port job right now, especially on cast iron heads..