306 v. 306 long rod

[blksn955.o]

So I am finaly ready to start buying parts for a rebuild. I want to go with a 306 long rod but I am running into some problems.

I call DSS racing and get a quote that I think it high since I can get a set of rods (Eagle 5.4 forged I beam rods form summit are 300ish) and then have 500$ to spend on pistons and still be cheaper then them (not a knock on DSS but I am a full time collage student and have to get the best parts that my pocket will allow at the best price).

So then I call CHP and tell the guy what I plan on doing, He tells me that the kit they have for a long rod 306 gives me a -20 in the hole, Now at this point I am thinking will from the avg. pistons I have looked at they run -4 to -7 and this guy is trying to sell me a set up that puts me at -20? I take the avg. -4 to -7 and then sub. the 331 crank (3.25) from the 302 crank (3.00) and there is the -20. So I am thinking he is selling me a 331 rod and piston? He then tells me to have 10 shaved off my block and that it will give me a comp. of 9.51:1. How can a -10 (after shave) still give me 9.51:1 with a flat top piston when all the other flat top pistons I have looked at with -7 are around 8.4:1?

I am realy looking into piecing together a kit of my own with talking to a piston co. However, at that point will it be worth all the headache, and will it be worth the power? I mean if I am talking about 15hp more over a standard 306 I will just go 306 (forged piston and rod of course).

ONe more question I noticed some rods had are bushed and some were pressed pins, I was wandering what is best and what is diff. on the piston if I use a bushed rod?

Thanks for any reply and sorry for the long read
Greg

 

[331 cobra]

Look on ebay, you can get a set of lunati 5.4" cap screw i-beams for about $230. But they have the small chevy 2.1" big end, so you will need to grind your crank.

You will need a piston with 1.300" compression height to get a zero deck.

Also,

The power probably isn't a big increase, unless you are spinning really high rpm when the rod ratio will help you.

You should call speedomotive, they do all kinds of strokers and probably know more about long rod 306's than the CHP guys.

 

[blksn955.o]

Thanks for the info 331, I want to keep the rods ford spec. but that is a good alt. Good info on the comp. height too.

anyone know what the diff. in power for a long rod 306 v. stock type 306? If I will only pick up 15hp or so I will just go for a stock type 306. ( know it depends on H/C/I) so here is my setup, gt40 heads, exploder intake,TFS stage1 cam.

 

[yellow1995Cobra]

I believe the DSS long rod 306 is capable of 7k RPMS, so with the right cam and heads, you will make far more power N/A then you will with a 6k rpm limit on the 306. You should talk to 2l8uluz, as he has the dss long rod 306.

Personally, i would go with the long rod, even if it costs a bit more. I just like the idea of being able to rev it high if i so please down the road.. But i would run a dart block as well, which is much $$$