241's VS 853's
 

ok heres the deal iam pulling my sister motor out of her formula here soon. i was intending on selling it on here but a friend of mine has a 04 GTO with a mild cam in it. befor he had the car they had nitrous on it. the car 20k on the clock. he developed a bad noise from it right after the warrentee died. he did a presure test on the cylinders and found that 1 had shit for presure( i dont know how much) he wants to trade me his motor for the one im pulling out, his car has a mild cam springs and all the good stuff but he is thinking from the nitrous it cracked a piston ring. now his car has 853 casting heads on it?

how do these heads comepare to the 241's.
and with a cracked ring would i need to bored the motor out to fix or just put new rings in?


what should i do trade him or just keep my motor?

You taking a big chance with his. Not sure on 853 but his should have had ls6 style I thought. I could be wrong though.

yeah his motor has a ls6 intake on it. i thought that the 853 casting heads were only 99 only..... i mean this motor is coming out of my sisters car and then we are puttin somthin eles in. he wants to trade that motor for his lol

his car should have come with 241 heads and an ls6 intake manifold.

I'd keep your motor....no telling whats going on with the one hes offering you.

Why trade a good running motor for something fucked up?

thats true and your right i didnt think that the 853's came on that... basically i dont need the motor that iam pulling out of my sisters car. his car has a cam and who knows the 853s could be ported and polished and if i could get away with just doing some rings and play around with it?......

I'd rather just do a cam kit on the engine coming out then taking a risk on someone elses damaged goods. Maybe trade + some money so you're doing him a solid getting his car back on the road but you're not getting fucked either.

yeah thats what i think i might do.... i might try to find him a highmileage long block ls1 and put that in there.... because he doesent wanna make it fast he just drives the thing lol..... then ill have both the motors and can play a lil more.

now is there any difference between the 853's to the 241's

I have one 853 and one 241 on my car that were ported using the same CNC program - they seem to be identical in that aspect. I doubt there's really much difference as cast.

yes there is a difference between the heads. the 853s were on the 98s. which is what I have. and the 241s are on 01 and 02 cars...I think. but more importantly, the 241s flow better. the 853s are the worst flowing out of the ls1 heads. I would prolly keep ur sis's engine and spend what u would fixin the other one on ur sis's engine. well good luck man.

well if theres anyone around that has a 5.3 longblock i can pick up cheap let me know.... ill put that bitch in there lol.... and i thought that the 98s have perimiter bolt valve covers these were center bolt and the 853's were on the the drivers side. the casting number was there..... iam confused about it very much

There is a lot of mis-information in this thread...
806 heads found on 98 cars and they are perimeter bolt, supposedly flow the worst. 853 and 241 heads flow the same. 243 heads are the best found on LS6 motors.

+1. also, i've seen 853 and 241 heads both on 00 cars.

853 vs 241 = no difference. they perform the same.

holy shite. haha. sorry about that guys. i was the one that said the 853s were on 98s. but yall are correct. i feel like a douchebag now. lol. but the casting numbers and years are now seared into my brain. once again i apologize.